From what I've been able to find. Its all going to depend onthe type of main gun HTC is planning on using
If it has the 75MM then the gun can stay. If they are using the 17 pdr anti Tank Gun then the coaxil gun was removed
Though some commanders added the 30 cal to the turret
"Sherman and Sherman Firefly:
The M4 Sherman if probably one of the best known tanks of the Second World War. It was developed from requests by the British for a tank with a 75mm gun in a rotating turret, instead of the sponson used on the Grant.
Two designs were considered, one using a cast hull and the other a welded hull, with both basing the engine and running gear on the M3 Grant. A welded hull model of the M4 was produced as the M4A1 and production began in February 1942, for delivery to the British. The basic Sherman has a turtle backed hull and a cast turret. The driver sat in the front left with an assistant driver/machine gunner alongside him. The engine was an air-cooled aircraft radial mounted in the rear of the hull. The drive shaft then passed along the floor to the transmission unit in the front, where it drove the track drive sprockets. The turret mounted a 75mm gun and a co-axial machine gun, with the gunner on the right, the commander behind him, with the loader/machine gunner on the left. The early Shermans have the characteristic of having rounded corners to the top of the front hull, while the latter one had "squarer" corners.
The 75mm gun soon became obsolete and the British re-gunned some of their Shermans with the 17-pdr anti-tank gun, which became known as the Firefly (Left). This gave them a method of knocking out the heavier German tanks at longer range. The Americans used a 76mm version to achieve the same. To accommodate the larger gun the coaxial machine gun was removed and a larger counter weight fitted to the back of the turret. Towards the end of the war the later models also had the hull machine gun removed so more of the larger 17-pdr ammunition could be carried. To provide protection against infantry some tank commanders often mounted a 0.30" Browning or BESA machine gun on the turret.
All models of the Sherman caught fire easily, which earned them the nickname of "Ronsons" by their crews and "Tommy Cookers" by the Germans, but it was the mainstay of the British Armoured Division until almost the end of the war, when the Cromwell had fully replaced it. A Diesel version was also produced which did not catch fire so easily, but this was not widely available. "
Now the only other question is if they are planning on using the Gas or Deisel version LOL
