Actually, the warbikes give them 4+ armor as well. So it truly is redundant.Take the eavy' armor off the bikers because the already have 4+ cover and feel no pain saves :grin:
Decent list overall, you should see some modicum of success, mostly for people not being able to deal well with nob bikers unless they really know what they're doing.
Zagstrukk is dangerous but fairly effective. I prefer snikrot kommandos for a unit to appear anywhere and assault