Heavy is right, if they are used right they do make a difference...once the wall is slightly weakend they will do damage, here are the sim results for the order of attacks heavy gave, i am using -25 luck
Wall Buster 1
Units: 0 0 xxxxx 0 0 xxxx 0 0 xxxx 0 0 0 1.006.000 649.000 1.004.000 20.600
Losses: 0 0 xxxxx 0 0 xxxxx 0 0 xxxx 0 0 0 1.006.000 649.000 1.004.000 20.600
Defender Units: 100000 100000 0 0 0 0 0 0 0 0 0 0 8.000.000 6.000.000 8.000.000 200.000
Losses: 815 815 0 0 0 0 0 0 0 0 0 0 65.200 48.900 65.200 1.630
Damage by rams: The wall has been damaged and downgraded from level 20 to level 19
Wall Buster 2
Units: 0 0 xxxxx 0 0 xxxx 0 0 xxxx 0 0 0 1.006.000 649.000 1.004.000 20.600
Losses: 0 0 xxxxx 0 0 xxxx 0 0 xxxx 0 0 0 1.006.000 649.000 1.004.000 20.600
Defender Units: 99185 99185 0 0 0 0 0 0 0 0 0 0 7.934.800 5.951.100 7.934.800 198.370
Losses: 818 818 0 0 0 0 0 0 0 0 0 0 65.440 49.080 65.440 1.636
Damage by rams: The wall has been damaged and downgraded from level 19 to level 18
Wall Buster 3
Attacker Units: 0 0 xxxxx 0 0 xxxx 0 0 xxxx 0 0 0 1.006.000 649.000 1.004.000 20.600
Losses: 0 0 xxxxx 0 0 xxxx 0 0 xxxx 0 0 0 1.006.000 649.000 1.004.000 20.600
Defender Units: 98367 98367 0 0 0 0 0 0 0 0 0 0 7.869.360 5.902.020 7.869.360 196.734
Losses: 868 868 0 0 0 0 0 0 0 0 0 0 69.440 52.080 69.440 1.736
Wall Buster 4
Attacker Units: 0 0 xxxxx 0 0 xxxx 0 0 xxxx 0 0 0 1.006.000 649.000 1.004.000 20.600
Losses: 0 0 xxxxx 0 0 xxxx 0 0 xxxx 0 0 0 1.006.000 649.000 1.004.000 20.600
Defender Units: 97499 97499 0 0 0 0 0 0 0 0 0 0 7.799.920 5.849.940 7.799.920 194.998
Losses: 871 871 0 0 0 0 0 0 0 0 0 0 69.680 52.260 69.680 1.742
Damage by rams: The wall has been damaged and downgraded from level 17 to level 16
Wall Buster 5
Attacker Units: 0 0 xxxxx 0 0 xxxx 0 0 xxxx 0 0 0 1.006.000 649.000 1.004.000 20.600
Losses: 0 0 xxxxx 0 0 xxxx 0 0 xxxx 0 0 0 1.006.000 649.000 1.004.000 20.600
Defender Units: 96628 96628 0 0 0 0 0 0 0 0 0 0 7.730.240 5.797.680 7.730.240 193.256
Losses: 924 924 0 0 0 0 0 0 0 0 0 0
Nuke
Attacker Units: 0 0 xxxxx 0 0 xxxx xxx 0 xxx 0 0 0 927.500 565.000 1.030.000 20.500
Losses: 0 0 xxxxx 0 0 xxxx xxx 0 xxx 0 0 0 927.500 565.000 1.030.000 20.500
Defender Units: 95704 95704 0 0 0 0 0 0 0 0 0 0 7.656.320 5.742.240 7.656.320 191.408
Losses: 1491 1491 0 0 0 0 0 0 0 0 0 0 119.280 89.460 119.280 2.982
Wall Buster 6
Attacker Units: 0 0 xxxxx 0 0 xxxx 0 0 xxxx 0 0 0 1.015.000 655.000 1.010.000 20.750
Losses: 0 0 xxxxx 0 0 xxxx 0 0 xxxx 0 0 0 1.015.000 655.000 1.010.000 20.750
Defender Units: 94213 94213 0 0 0 0 0 0 0 0 0 0 7.537.040 5.652.780 7.537.040 188.426
Losses: 936 936 0 0 0 0 0 0 0 0 0 0 74.880 56.160 74.880 1.872
Damage by rams: The wall has been damaged and downgraded from level 15 to level 14
Nuke
Attacker Units: 0 0 xxxxx 0 0 xxxx xxx 0 xxx 0 0 0 927.500 565.000 1.030.000 20.500
Losses: 0 0 xxxxx 0 0 xxxx xxx 0 xxx 0 0 0 927.500 565.000 1.030.000 20.500
Defender Units: 93277 93277 0 0 0 0 0 0 0 0 0 0 7.462.160 5.596.620 7.462.160 186.554
Losses: 1595 1595 0 0 0 0 0 0 0 0 0 0 127.600 95.700 127.600 3.190
Nuke
Attacker Units: 0 0 xxxxx 0 0 xxxx xxx 0 xxx 0 0 0 927.500 565.000 1.030.000 20.500
Losses: 0 0 xxxxx 0 0 xxxx xxx 0 xxx 0 0 0 927.500 565.000 1.030.000 20.500
Defender Units: 91682 91682 0 0 0 0 0 0 0 0 0 0 7.334.560 5.500.920 7.334.560 183.364
Losses: 1609 1609 0 0 0 0 0 0 0 0 0 0 128.720 96.540 128.720 3.218
Wall Buster 7
Attacker Units: 0 0 xxxxx 0 0 xxxx 0 0 xxxx 0 0 0 1.015.000 655.000 1.010.000 20.750
Losses: 0 0 xxxxx 0 0 xxxx 0 0 xxxx 0 0 0 1.015.000 655.000 1.010.000 20.750
Defender Units: 90073 90073 0 0 0 0 0 0 0 0 0 0 7.205.840 5.404.380 7.205.840 180.146
Losses: 1011 1011 0 0 0 0 0 0 0 0 0 0 80.880 60.660 80.880 2.022
Damage by rams: The wall has been damaged and downgraded from level 14 to level 13
Nuke
Attacker Units: 0 0 xxxxx 0 0 xxxx xxx 0 xxx 0 0 0 927.500 565.000 1.030.000 20.500
Losses: 0 0 xxxxx 0 0 xxxx xxx 0 xxx 0 0 0 927.500 565.000 1.030.000 20.500
Defender Units: 89062 89062 0 0 0 0 0 0 0 0 0 0 7.124.960 5.343.720 7.124.960 178.124
Losses: 1632 1632 0 0 0 0 0 0 0 0 0 0 130.560 97.920 130.560 3.264
Nuke
Attacker Units: 0 0 xxxxx 0 0 xxxx xxx 0 xxx 0 0 0 927.500 565.000 1.030.000 20.500
Losses: 0 0 xxxxx 0 0 xxxx xxx 0 xxx 0 0 0 927.500 565.000 1.030.000 20.500
Defender Units: 87430 87430 0 0 0 0 0 0 0 0 0 0 6.994.400 5.245.800 6.994.400 174.860
Losses: 1647 1647 0 0 0 0 0 0 0 0 0 0 131.760 98.820 131.760 3.294
Nuke
Attacker Units: 0 0 xxxxx 0 0 xxxx xxx 0 xxx 0 0 0 927.500 565.000 1.030.000 20.500
Losses: 0 0 xxxxx 0 0 xxxx xxx 0 xxx 0 0 0 927.500 565.000 1.030.000 20.500
Defender Units: 85783 85783 0 0 0 0 0 0 0 0 0 0 6.862.640 5.146.980 6.862.640 171.566
Losses: 1663 1663 0 0 0 0 0 0 0 0 0 0 133.040 99.780 133.040 3.326
Nuke
Attacker Units: 0 0 xxxxx 0 0 xxxx xxx 0 xxx 0 0 0 927.500 565.000 1.030.000 20.500
Losses: 0 0 xxxxx 0 0 xxxx xxx 0 xxx 0 0 0 927.500 565.000 1.030.000 20.500
Defender Units: 84120 84120 0 0 0 0 0 0 0 0 0 0 6.729.600 5.047.200 6.729.600 168.240
Losses: 1679 1679 0 0 0 0 0 0 0 0 0 0 134.320 100.740 134.320 3.358
Wall Buster 8
Attacker Units: 0 0 xxxxx 0 0 xxxx 0 0 xxxx 0 0 0 1.015.000 655.000 1.010.000 20.750
Losses: 0 0 xxxxx 0 0 xxxx 0 0 xxxx 0 0 0 1.015.000 655.000 1.010.000 20.750
Defender Units: 82441 82441 0 0 0 0 0 0 0 0 0 0 6.595.280 4.946.460 6.595.280 164.882
Losses: 1057 1057 0 0 0 0 0 0 0 0 0 0 84.560 63.420 84.560 2.114
Damage by rams: The wall has been damaged and downgraded from level 13 to level 11
Nuke
Attacker Units: 0 0 xxxxx 0 0 xxxx xxx 0 xxx 0 0 0 927.500 565.000 1.030.000 20.500
Losses: 0 0 xxxxx 0 0 xxxx xxx 0 xxx 0 0 0 927.500 565.000 1.030.000 20.500
Defender Units: 81384 81384 0 0 0 0 0 0 0 0 0 0 6.510.720 4.883.040 6.510.720 162.768
Losses: 1803 1803 0 0 0 0 0 0 0 0 0 0 144.240 108.180 144.240 3.606
Damage by rams: The wall has been damaged and downgraded from level 11 to level 10
Nuke
Attacker Units: 0 0 xxxxx 0 0 xxxx xxx 0 xxx 0 0 0 927.500 565.000 1.030.000 20.500
Losses: 0 0 xxxxx 0 0 xxxx xxx 0 xxx 0 0 0 927.500 565.000 1.030.000 20.500
Defender Units: 79581 79581 0 0 0 0 0 0 0 0 0 0 6.366.480 4.774.860 6.366.480 159.162
Losses: 1926 1926 0 0 0 0 0 0 0 0 0 0 154.080 115.560 154.080 3.852
Damage by rams: The wall has been damaged and downgraded from level 10 to level 9
Nuke
Attacker Units: 0 0 xxxxx 0 xxxx xxx 0 xxx 0 0 0 927.500 565.000 1.030.000 20.500
Losses: 0 0 xxxxx 0 0 xxxx xxx 0 xxx 0 0 0 927.500 565.000 1.030.000 20.500
Defender Units: 77655 77655 0 0 0 0 0 0 0 0 0 0 6.212.400 4.659.300 6.212.400 155.310
Losses: 1949 1949 0 0 0 0 0 0 0 0 0 0 155.920 116.940 155.920 3.898
Damage by rams: The wall has been damaged and downgraded from level 9 to level 8
Nuke
Attacker Units: 0 0 xxxxx 0 0 xxxx xxx 0 xxx 0 0 0 927.500 565.000 1.030.000 20.500
Losses: 0 0 7500 0 0 2500 300 0 300 0 0 0 927.500 565.000 1.030.000 20.500
Defender Units: 75706 75706 0 0 0 0 0 0 0 0 0 0 6.056.480 4.542.360 6.056.480 151.412
Losses: 2085 2085 0 0 0 0 0 0 0 0 0 0 166.800 125.100 166.800 4.170
Wall Buster 9
Attacker Units: 0 0 xxxxx 0 0 xxxx 0 0 xxxx 0 0 0 1.015.000 655.000 1.010.000 20.750
Losses: 0 0 xxxxx 0 0 xxxx 0 0 xxxx 0 0 0 1.015.000 655.000 1.010.000 20.750
Defender Units: 73621 73621 0 0 0 0 0 0 0 0 0 0 5.889.680 4.417.260 5.889.680 147.242
Losses: 1317 1317 0 0 0 0 0 0 0 0 0 0 105.360 79.020 105.360 2.634
Damage by rams: The wall has been damaged and downgraded from level 7 to level 3