Always nice to see the Ogres on parade, those look great!
Camo on them isn't particularly important anyway, visual detection isn't really a big concern at that size vehicle. At this tech level, I presume even smaller vehicles don't worry about visual spotting, every other detection method is going to pick them up first anyway.
But ages ago, I did figure out the trick to nice looking camouflage on the table. After doing the camo and any weathering, then go back and highlight the all edges of the vehicle to make its shape visibile again. I often dry-brush edge lines with flat steel, or a very light shade of colours used in the camo scheme. Lining crevices with a .005 Micron Art pen helps a lot too.
The same sort of highlighting that was done on these models would make camo pop too.