[@agentmanatee] I am well aware of that, yes. That's probably part of why Valius would've been allowed to live at all, since his basic superhuman physique alone makes him markedly more powerful than any normal Tech-priest, never mind how he's improved upon that over and over again over time. I'm just saying, it seems rather unlikely that the Librarians and Techmarines have much to do with each other thematically under usual circumstances, and it therefore seems unlikely that they interact with one another too much beyond the basic necessities of supplying technology and general niceties that one should show a fellow battle-brother. I'd have further proposed at this point that the general strangeness of the Techmarines would (going by what 40k's canon states, mind) further alienate them from their fellows in most chapters that weren't highly involved with the AdMech in the first place, but that point is moot considering the high degree of cooperation between the Warp Skulls and AdMech.

Basically, I'm of the opinion that Constantine and Valius wouldn't normally have interacted very much, save for Valius' weird in-between state, and depending on how involved Constantine gets with Valius' reprogramming and psyker training, they may not interact all that frequently anyway; as stated, Rooke's probably considered more of a dangerous tool than a living being at the story's beginning by the majority of the chapter, certainly the veterans and command staff at any rate, and has probably been very alienated from both his fellow Techmarines and the Librarians he's basically been forced to interact with by his new abilities.