God I hate BB.
Thankfully I've never been combat nor would I wish to be. Thankfully it doesn't take combat experience to realise that those small arms won't do any damage to a modern tank.
In any case, the argument was how much luck should play a role in combat. I can just as easily make the example of the polish lancers vs zee germans.
Point is, hood vs Bismark, sure - similar and doesn't need a lot disbelief. The actual relevance comes down to whether you think a beam/pulse laser vs armor 12+ is:
A) a lancer or some small arms vs 1 foot of armor
Or
B) hood vs bismark
Whether you choose A or B is really an adhoc decision based on personal/group preference - just don't try to prove one is more logically valid however. Besides, there are tons of 4d6 and higher weapons/bays that are designed to penetrate higher armor so it's not like we need to ADD a house rule to make lower class weapons more effective.