ROM is a very small number. The majority of people that were part of ComStar had no part of that, and thus weren't any more or less villainous than anyone else.
My point was that, in all but a couple small but notable exceptions, members of C* have been presented as mustache-twirling villains. Almost the entirety of ROM, a small number yes, but also, a good chunk of those first-run C* expats that became WoB were just fine with being villains. Regardless of their reasoning behind it, it wasn't just Cameron and The Master that were good with going genocidal on the Clan Homeworlds. The average adept is -probably- not more or less evil than anyone else and, possibly, the average demi-precentor follows suit.
But it's like super-successful mercenary units; these are generally the exception to the rule, not the rule itself per every iteration of a mercenary sourcebook or novel. For every GDL or Northwind Highlanders, there are hundreds of units that don't survive their first year. Yet, no one wants to read about the failures, and failures don't lend themselves to go serialization in multiple books. Same with the trope of the "evil C* Precentor" or at least on the evil-leaning spectrum, presented in almost every novel where C* (and later the Word) make an appearance. And the troops under the command of these displayed Precentors rarely have qualms about doing pretty not-good things.
But back to the line that spurred any of my comments at all "you mustn't think of Comstar as devious schemers" - no, but really, you absolutely should. From their first appearance to the last appearance, ComStar has -literally- been known as the "devious schemers" faction. It's the only way they were able to hold Terra for as long as they did. Even if not outright evil, you can bet your hard earned C-bill (controlling finance is devious!) that any time C* has encountered any real outside of the Sphere itself, it has looked for ways to use that new realm to C*'s advantage, not as an altruistic & benevolent organization.