Question About Painting Armor & Military Vehicles

This may sound like a stupid question, but I am curious as to how y’all paint your armor and fighting vehicles. I am starting an Italeri Hummer this morning and am curious as to how far I should go in terms of painting the body parts and so forth before gluing them together. I want to build a Desert Storm weathered vehicle so it will be a sand color with alot of desert weathering.

Any ideas and input is greatly appreciated.

On something like that, I would paint the interior only before and during assembly. For that era, the CARC green. Exteriors I prefer to paint and weather after assembly completion.