Based on the length of an existing barrel segment, now that makes sense. I didn't realise the 3.7" was built up with a segmented, or even separate, barrel liner. Anyway that would explain the barrel length and the resulting need for a counter weight, the whole thing just seems to make the 25pdr as trialed in the AC3 a more sensible approach as that weapon excelled in both direct and indirect fire.
On the 95mm not being intended for direct fire, while I realise CS tanks could be used for indirect fires, I was under the impression that the reason for their existence was to provide direct, high explosive, fire support against enemy emplacements (bunkers, pillboxes, MG nests etc.), AT guns and infantry, the sort of targets the 6pdr was not well equipped to engage. Engaging such point targets requires a degree of accuracy that cannot be achieved with indirect fire, here increased velocity and a flatter trajectory would help but is not vital.