here are translations into old danish, as good as I could

reiters with carbine = Landryttere medt lange rør
reiters with pistol = Landryttere medt sadelrør
halberdiers = Hellebaardierer

spell rør as roer if you don't want that danish letter

lange rør is "langroer" in old dutch btw, I suppose in german as well.