[@Draken] Well, unless the protector was incapacitated, I don't believe that Ilya would need to use the water shield on anyone other than himself. Not to mention, unless we're in a relatively warm area, that water will be ice. And by relatively warm, I mean not freezing, since freezing is the common temperature. It does make sense, though.
As for Oren, he'd be somewhere that the other inquisitors are at. While the enemy is distracted by another opponent, he'll blindside them. He can hold his own one-on-one, but his focus is to eliminate them quickly, not anything else.

And when it comes to separating the warbands... the Empire can't be left defenceless, but the attack is too much for one Warband alone.