my method is to work on two or three thing at a time. sometimes when there's too many things, you can't sustain interest, and you can't focus on quality.
also, let the arma 2 stuff go, unless you put in the effort to upgrade them to arma 3 standards, they'll look really out of place. better to port over from a2oa onwards, because they're much higher quality. basically, right at the time they made oa, pmc, baf, they either hired a bunch of new artists, or they started making brand new models from scratch. because the clothing is just much more detailed, realistic and optimized.