Conditional

1. If we had to hazard a guess, our money would be on the larger buffer, at least for the single-user gains. (How come I have a present tense 'gains' from out of no where? Is this correct?)

Why not like this?

2. If we had to hazard a guess, our money would be on the larger buffer, at least for the single-user would gain. (Howdoes the meaning of this sentence differ from #1?)

Or like this?

3. If we had to hazard a guess, our money would be on the larger buffer, at least for the single-user gained.

Thanks!!!