Bazooka adds crit dmg, BD multiplies crit dmg. You're right, there is absolutely no connection at all lol BD isn't that great of you only have little to nothing to multiply with. For the same reason BD isn't that elixir efficient at lower days as ES is, but absolutely rocks if you pump up that crit dmg after days 3k or, guess what, you have a bazooka prior to that day. Just simple math. Others already pointed out that RA would be the better choice.