I think if you want to stick to historical accuracy at all, use your tank stats for the mech inf and leave out tanks. The only “tanks” used in this campaign were very light tanks, even then with limited mobility. The jungle terrain was not conducive to tanks at all. But mech inf kinda represents light tanks IMO, so that would be ok, in limited numbers. Also, any mech inf or tank should require all the space on a transport and should not be able to board a destroyer.
And with those stats (1 tank equals full transport) there is no reason at all to buy a tank over two INF. Same land attack, same space on transports, plus harder to destroy (two INF requires two hits). A possible idea would be to have the tank take up one space but keep the stats. That way it might have its uses.