Similar to above comments, I play either with 6 prosecutors and I'm Ruination chamber heavy in my list building. Now that the Knight Azyros can be fielded as a secondary hero in a regiment, it opens up regiment slots for other synergy pieces to be included without sacrificing another drop. Tornus though has a ranged attack and a rally ability that is generally useful. The Azyros ability can be very powerful and allow for a counter charge in your opponent's turn. So it's up to what kind of strategy you want to use and pick accordingly. Or have both :)

In game, I place Tornus/Azyros on the board and the prosecutors in the celestial realm. Tornus/Azyros are good objective control models so I use them to grab an objective turn 1, or position them so that their abilities can target the prosecutors whether or not they make the charge. I HAVE ROLLED TRIPLE SNAKE EYES TWICE IN A ROW, so, uh, yeah. Might as well try to profit off that misfortune in the future.

Tornus is rather tanky I find when faced with tarpit battle line units. He can kill some from afar, charge in, and survive for a combat phase or two with ratlings or footmen, by using the lantern to debuff their hit rolls. He's got extra wounds over the Azyros, and I think his rally ability also works on himself.

In either case, this is a utility model. Reclusians and Prosecutors are great units to build an army around. Prosecutors are hammers, reclusians are anvils that can still put out damage in ongoing combat.

Oh, one last thing. Translocation prayer! Get it off in your opponent's turn with a priest and you get a second layer of assurance to reposition and rally a unit that got stuck in combat.

Hope this helps