To some extent we have miscast management rolls to bail us out, so the risks might end up being slightly lower. On the other hand it's important to remember that the more Riders we have, the worse our micasts will we when they happen, because we will have 3 or 6 or 10 loose monsters trying to eat us in addition to whatever it was we were fighting rather than just 1.
Has Boney confirmed anywhere that every bound apparition we're trying to summon is released on a miscast? My understanding is that it can miscast normally (but is less likely to) and then there's a risk of it going off the leash. But if the risk is that at least one goes off the leash (which becomes more likely as we add more chances) that's a very different proposition to every Rider going off the leash at the same time on the basis of one roll.
We also need to consider than Bodyguard will quite often compete against the well-known basic spell Hire Mercenary. Mathilde usually gets into the kind of situations where that is impractical, but for a hypothethical squishy BM-grade Grey the option of trading coin for protection and permanently dragging along the result in meatspace will be available more often.
Grey Wizards are in a uniquely poor position to hire mercenaries - it's a justifiable expense, to be sure, but getting the money to
make that expense is going to be difficult while operating within the confines of the Vow of Poverty, and even harder to manage on an ongoing basis.
They also tend to lack the contacts within the Imperial Army that the Bright Wizards have. While a more formal requisition is possible in extreme circumstances, the sorts of people who can do so somewhat casually are very likely to have their own Battle Magic, and the situations where it's justified on review are rare even for them.
No, merely having Magic 7 or being a respected magister is not enough. The college does not allow people to learn Battle Magic easily.
Mathilde actually had a "is this allowed?" roll when she tried to learn the very basics, and that happened after she leveled Sylvania, became a Loremaster and did a bunch of high-impact things.
Consider that from an Imperial perspective what happened after Abelhelm's death was that she went mildly insane from grief, forcibly took command of a reasonably large military force to push forward in hostile territory rather than consolidating her holdings, and then was summarily dismissed by her employer's successor.
At this point she came back just long enough to be declared a free agent, then fucked off out of the Empire entirely for several years to go live amongst and work closely with a culture whose most prominent feature from an outside perspective is the bloody and singleminded pursuit of vengeance for slights against them, where she evidently fit in better than she ever had.
Did Mathilde do a lot of good while she was away? Obviously. But it was mostly out of sight of Imperial eyes, and there was plenty of cause for anyone who didn't know her personally to be suspicious of her motives.
