Indeed, although the same is true within the Inquisition itself. Once you've reached a certain level of veterancy and influence with a far-reaching network of other Inquisitors - once you can call yourself an "Inquisitor Lord" - things do get a lot easier and you'll be able to get away with more personal quirks because, for example, the Ordo Sicarius will prefer not to antagonise you just for a single Assassin.
Yet likewise, before reaching this point in your career (which very few Inquisitors do), you're not going to want to antagonise the Ordo Sicarius by effectively stealing Assassins as sexy companions for your personal retinue.
Or maybe you do, but then you're going to have to deal with the consequences of such audacity.
It comes down to how clever the individual Inquisitor is, and whether they try to avoid needless trouble with their peers, or whether they simply don't care and are too focused on some self-defined goal, exploiting their newfound authority without regard for on whose toes they might step by doing so.