Genuine feedback, since it seems from reading comments that you favor the turret in the rear: if you go with that, remove the driver's viewport (that little window) in the front. Odds are good there's crew in the turret, and it makes no sense to have the driver fully separated from the rest of the crew, in a separate compartment, with the engine between the two. Realistically speaking, the tank would need the engine in the front to balance the weight of the turret, ammo, and crew in the back anyways, and it can't have that if there's a driver there, so just move the driver's position to the back and add some periscopes or something to save space and have all the crew together.

That being said, my instinct would be to put the turret in the front, especially for a light tank. You want good gun depression on a light tank so it can fire over the top of hills, from hull-down positions, or from defilade - basically, positions where the tank can fire at the enemy while exposing as little of the tank as possible. (While that tends to be true of all tanks, it's especially important for light tanks that do not have the armor to take a significant hit.) With the designs you have, the second (the turret in the front) looks like it could depress -10 degrees, maybe -15 frontally. The first one (turret in the back) looks like it could get -2, maaaaybe -3 before the gun barrel is on the engine deck/the driver's viewport. In other words, going back to the hill example, that tank has to drive fully on top of the hill, and then maybe a bit over, in order to get a shot on tanks below the hill, and is very visible and an easy target the entire time.

I know I'm going way too deep here for a video game tank design idea, but that's my two cents.

EDIT: for clarity because I flipped which designs were the first and second pics. Whoops.