Maybe they should have use the weird plastic clamps from the later days of ARAH vehicles. That would have accomodated either style, as it just flexes around the figures lower torso to hold them in place.

I personally never liked those back in the day, but they could be useful in holding figures in place in some applications.

Could these vehicles be delivered cheaper without the figures? I remember vehicles without figures a long time ago being at least $3 to $5 cheaper...

But then again, mixing poor in with good sells well for them...