If I had any magnets I might have considered that, as it is I just cut and glue arms. So far I've got Archers and Riflemen with Warhammer arms, Archers and Warhammers with Rifleman arms, and Riflemen and Warhammers with Archer arms. That pretty much covers the spread.
I put my Longbow back together rather than keep the arms on an ARC, so that's no longer part of the chop shop. Been slowly working on painting these guys up, too - I'm going to repaint the golden Banshee in an even shinier color to please the mighty Char, and gave it lancemates of a Super Rifleman, a Thunderbolt with ARC-5R arms, and a Warhammer with the Tbolt's arms.