why not;
a) mount your 'judge squads' in repressors as that's their tank afterall?! and it even comes with a flamer too!
b) take one or two squads w/grenade launchers for a little bit of added punch... the 'frag' rounds could ideally be tear gas canisters with more highly concentrated corrosives to subdue the enemy, while the heavier 'krak' round could be a heavy 'man-stopper' round???
c) for the 'marshal', make him an allied daemonhunter inquisitor and thus gain access to a power fist or thunder hammer! (or heavy shock maul perhaps?!)
d) an inquisitor lord and his retinue could count as a senior judge officer leading a heavy supression squad? heavy bolter servitors for a bit of long-ranged ability to cover your transported troops maybe?
also, in any friendly game, why not ask your opponent if they'd allow you to count your shotguns as having the man-stopper rounds as described in codex: dark angels?
it's not game-breaking in any way, but it would be so in character for a judge force! i know i'd let you do it as it would simply be a fun way to add to the wonderfull narrative of your force!
cheers!