You can do a far superior job of painting with the truck dissassembled, especially with the fat fenders, between cab and bed, doors, firewall. You can put a gasket or welting between sheet metal parts and have a clean seam. Your not masking off parts that were not removed. Much more labor intensive than painting a vehicle assembled and far superior. IMO.
If your worried about a difference in paint color, buy a gallon of paint, stir well, measure accurately and paint cab, doors, hood, bedsides,
first. If you need more paint, any slight difference in color won't be perceptable on fenders, or tailgate. IMO.
