@Leith
i cant think of 1 way to force the mage to expose himself. Sarcasm again ?
example:
Force 18 spirit:
1. service use "Search" Power and find Runner X
2nd service when you found Runner X obliterate him
Are we talking PC vs spirit or NPC vs spirit. If the former, warn the PCs they're pissing someone off who can do the thing and let them decide.
If the latter, yes, you can force the PC mage to expose himself.
1) if the task is mindane and complex the mage will at the very least need to astral project to supervise spirits exposing them to astral attack,. Even a low force patrol spirit (3-4) should create some tension.
2) wards. Spirit can't cross without raising the alarm but the mage can. The mage must physically go to the place before unleashing hell.
3) astral/ matrix tracking. Pretty much what you said but without the spirit. If the bad guys show up at your door or ambush you on the street, you're exposed.
Btw, I'm not saying that a mage can't deal with this stuff, just that it is possible to challenge angel summoner without demon summoner. Or at least a demon summoner of comparable skill.
Also, also, this doesn't really address the issue of the street sam playing babysitter until the mage can summon his army.