How I do armor is this.
Paint the road wheels and assemble. Set aside.
Assemble the hull and paint the base color. Paint any tools, cables, etc. Set aside.
Assemble the turret and paint the base color. Set aside.
Add road wheels to the hull and put the turret in place. Paint the camo colors.
Paint the tracks and assemble runs and add to the road wheels.
Glosscote and add decals.
Apply wash to panel lines, recesses, the base of raised details, etc. Let dry.
Dry brush to bring out highlights.
Seal with Dullcote.
Add smoke stains and dust with pastel chalk.