There are plenty of examples of aircraft operating off of a big open field (no concrete runway) in every theatre, by every side in the war. You truck in your fuel and ords and either put it in a tent or dig a hole for it to live in until you need it. Instead of having a re-arm pad at a vh, I would just rather have it that aircraft could consume vehicle supplies to trigger a 30-second rearm cycle. What this would do is let you send vehicles full of supplies forward and position them at some open spot to let friendlies come in and rearm. It might create some interesting situations if done via LVT on an island near your target.
Those were airfields though, not vehicle bases, and the lack of formal runways means nothing. High performance fighters cannot use the fuel that vehicles use.
Ok, compromise. You can rearm at vehicle fields, but you have to wait for the proper fuel, ammo if appropriate and ordnance to be trucked in. Say, about six hours before rearming is complete.