Not to combine when I need to hit the main battery? Wow.
It's better to take two 1:1 shots than one 2:1 shot. Typically, the best use of infantry is to complement other units to get exactly 1:1 shots and avoid wasted factors. But given the MB's high defense, it's usually a target that you'll want to combine fire on.
Let me know if you're up for a FTF game over the holidays. I'm game.