Ah, you're missing out on the proper grammatical relations of verbs and their objects here. Refer to this:

вооружать рабочих, вооружаться самим, вооружать рабочих самим

Самим is, how do you call it properly, an inderect object in both cases there and рабочих is your direct object, which is in boringly mundane accusative there. Here's a nifty little tip though, reflexive verbs, grammatically speaking, don't generally go well with direct objects because this reflexive form is already comprised of the verb in its basic active form and the reflexive себя, which is exactly what turns the action a verb describes back at its subject. Like this вооружать себя-> вооружаться. Ся is a shorty for себя if you will. This reference is strictly grammatical though, symantically a reflexive verb "taken apart" won't always mean the same thing. Вооружаться = вооружать себя, however.