In relation to the use of armoured cars to represent mechanized infantry divisions, I am in agreement, where such a representation would be historically accurate and representative of the most commonly used support vehicle for such divisions.
In the case of the Italians, I agree that indigenous halftrack production and use was far less extensive than that of armoured cars, and so an armoured car sculpt would be the best representation of this Italian unit. The AB41 is, in my opinion, the best choice for the sculpt as well, given the scale of its production and status as one of the more historically well-known Italian armoured cars.
In the case of the Soviet Union, while FMG indicated that a halftrack would perhaps be the best sculpt to represent Soviet mechanized infantry, I would be willing to accept an armoured car for this unit as well. Soviet armoured car designs were more widely used and effective than Soviet-built halftrack designs, and while the USSR did make extensive use of Lend-Lease US halftracks, I would personally prefer an indigenous Soviet design. My preference for an armoured car here would be for a BA-64.
I have to disagree with FMG regarding the alleged inappropriateness of a halftrack to represent Japanese mechanized infantry. Development of Japanese halftracks began much earlier in the war than 1945; I believe development and production began in 1940 or 1941. The Type 1 Ho-Ha was in service as early as 1941, although it was later in the war until they were produced and saw action in large numbers. To me, this is the real-life representation/equivalent of a hypothetical ‘Japanese player’ choosing not to produce many mechanized infantry units in favour of other units (such as aircraft and infantry) - the decision of this ‘real life Japanese player’ (for lack of a better term) not to produce more Ho-Ha’s earlier in the war does not necessarily have to translate into board game play; the board game player may produce more Ho-Ha’s and sent them to the front, and in doing so, alter the historical choices of the ‘real life Japanese player.’ Overall, I do not see the choice of the Type 1 Ho-Ha as an inappropriate choice for Japanese mechanized infantry by FMG, and I shall stick to this choice (although I certainly wouldn’t refuse to buy the set if FMG chose a different sculpt). Finally, no Japanese armoured car design has ever struck me as being particularly inspired or iconic. I suppose FMG could use a tankette, but I personally wouldn’t want to see another tank mold used to represent any nation’s mechanized infantry, even if it was just a tankette (just my subjective opinion though).
For German and the US, I would like to see a halftrack, and I would be fine with replicating the OOB units (the WoTC US and German halftrack sculpts were not particularly detailed, IMO, and I never want to use them again). If FMG really wants to change the German OOB sculpt, than the SD Kfz 250 could substitute for the SD Kfz 251, I guess.
For France, I would choose an armoured car, specifically the P178.
For the UK, I would choose the Universal Bren Carrier.
I don’t care much about China - just reprint an appropriate armoured car from another nation (maybe use the BA-10 for both the USSR and China).
Reprint the UK mold for ANZAC, and maybe Canada.
That’s all for now.