Dawn of War Codex

Okay so I'm really really new to this game, but have some experience with other RTS.
The thing that confuses me the most right now is the text for one of the Strike Squads upgrades.
The Nemesis focus says that after you upgrade it, you can't upgrade your ranged weapons, but I did read some people discuss if PsyCannons or Nemesis focus are better, can I not get both with upgrading PsyCannon first? Does Nemesis focus also cancel all previous ranged weapon upgrades?
Or if I can get both that way, why shouldn't I? I thought GK were the faction you upgrade the most.
Tyvm for answering

Actually, the Nemesis focus upgrade isn't in the game any more. Have you downloaded 2.3?

Anyway, to answer your question, the ranged upgrades for the Strike Squad would be removed by the Nemesis focus.

Welcome to Elite, feel free to ask any other questions you might have

Okay tyvm
Hmm there seems to be a new upgrade for them I just noticed, does that one stack because it also is ranged damage upgrade?
Gonna play some 2.3 now xD

Yep, it will let you keep your ranged upgrades and gives all of your ranged weapons 15% increased damage.