My man this was in my initial response to your idea:
That's fine but then there's no reason for the M5 to be in T2 since it serves no purpose. Why would you spend 30 fuel on it and delay your T70 by a minute and a half? It might have been viable if the M5 could heal units inside so you could skip medics, but since the balance team denied that ever happening then there's really no use getting the M5 before T3.
It just isn't a good fit. I think it's better to just have the Maxim in T2 and require T3 since it doesn't do anything other than delay the maxim. Yes it makes T2 a bit weaker but you can compensate for that by automatically unlocking Molotovs once T2 is up.