I react a little allergic to that general arm lead bashing!
After a few years here, I believe this might be another lost-in-translation thing.
Most of us know that the whole body leads, that just about any part can advance or recoil to communicate, that almost any part can be the point of contact for this. But it's all attached, so you don't freeze your whole body en bloc and (say) shove your partner with just a leg or just an arm. What those of us who have English as a first language mean by "arm leading" is literally standing still in space and yanking your partner around using only your arms, like two pistons emanating from an immobile wall.
We're talking quality of movement here, so I'll say that nobody who practices movement disciplines (pick your favorite) would ever recommend that sort of lead. It is dangerous for the follower's spinal column.
I strongly, strongly suspect that you – as someone with an injury – are not proposing to do that! I suspect that you're talking more about arms defining the limits of movement (sides and back of a "frame," with the torso covering the front), arm elasticity (common in off-axis movement), arm sliding (useful in turns), and maybe arm loops (typical of soltadas), all of which are necessary for tango and all of which implicate the shoulders, torso, and entire body by virtue of being attached.
I doubt that you're saying it's okay to grab your partner and shove them with arm strength, as you might in a barroom brawl, as the entirety of the lead. If you
are saying that, well, you should know that today's teachers freak out if you do it and present it not as "something you can do at times, but you have to learn when" but simply as "wrong, and never to be done."
Anatomically seen, its a form of spiral dynamics.
Yes! Spirals are the best.