Man, I feel like I want to rework the Inaban Defense Force and center it more around its infantry, with four mechanized brigades and only eight gun-vehicle companies among them. I can't shake the thought that even a Type 74 tank is a step too far for Inaban heavy industry, and that they'd build something more like a tank destroyer for the role rather than an MBT.
I'm also thinking that the 12-man squad is too big to build an APC around. I'll grant that an M113 can carry that many, but I've been looking over the Swedish infantry platoon here:
It's got a pretty strong loadout for its size with each squad of six carrying the following:
Squad Leader: Ak 5C with M203
Deputy Squad Leader: Ak 5C with M203
Anti-Tank Gunner: Ak 5C, Carl Gustaf
Anti-Tank Loader: Ak 5C, AT4
Machine Gunner: FN MAG
Combat Lifesaver/Rifleman: Ak 4D, AT4
The Ak 5C is a 5.56mm assault rifle, while the Ak 4D is basically a scoped HK G3 making for a DMR in each squad.
I've been eyeballing the CV90 for a while now, and wondering about what a 1970s version might look like. Keep the 40mm since the Bofors gun is a decades old classic, and try to cram as much armor on as possible. It'd be a case of the Inabans being protective of their infantry, and their small military would focus on keeping the soldier alive hence the heavier IFV. Use that as the basis for a typical family of vehicles; IFV, tank destroyer, mortar carrier, command post, engineer vehicle, antiaircraft vehicle, and artillery piece.