Which was worse:
..... Mid engine with front sprocket drive (ala. Bren/Universal Carrier)?
Rear engine with front sprocket drive (ala. Oxford Carrier)?
..... front engine with rear drive sprocket (ala. Canadian experimental Bobcat APC)?
They all wasted valuable cabin space. Bobcat proved frightfully noisey and clambering over the aft differential was difficult for heavily-laden infantrymen.
Building a serious APC/IFV earlier starts with asking poor bloody infantry what they want.
Cold War - and Gulf War - dogma says that APCs need front engine, front drive and rear ramp for easy exits.
That would require an enlarged, front-drive, front-engine Universal Carrier with a rear ramp. Add a complete second boggie and overhead cover. Maybe develop the infantry ramp from a mortar-carrier.
In other threads, I have speculated about a 6 x 6 wheeled APC based on a Canadian Military Pattern truck chassis ..... try to picture a CMP armoured ambulance enlarged to carry 9+ infantry under an armoured roof. Make doors wide enough for heavily-laden infantry they exit quickly.
Another thread speculates about Valentine Archer and (fictional) Bishop 2 SP guns de-frocked to carry ammo and gunners .... later infantry. Turning the driver’s seat the face the engine would free up the old glacis for decent-sized doors.
Side vision-blocks improve situational awareness for infantry.
Firing ports are great for morale, but kill few enemy. Far wiser to leave killing to a dedicated MG turret ...... .30 caliber minimum ...... Browning .50 caliber if that caliber is already coming through the existing supply chain.