Imperium VS Imperium

I am curious how often imperium armies actually fight against eachother. For example, I know that GK and SM often kill guardsmen that have seen daemons, and that the DA and SW have some feud going on.

However, I am curious how often the other armies fight. With it being on of the most played armies, a common scene in GW stores is the SM player fighting another SM player.

As far as fluff is conserned, do Space Marines really ever fight eachother? How about Inqusition/SoB/GK against Marines? SoB vs Inquisition/Marines? The list can easily go on from here.



I know about the Heresy, and that there are often defectors to the Tau and Possessed Guardsmen, but those aside, do loyalists ever fight loyalists, or is that just a scene for the gaming store due to the popularity of Marines and the fact that four armies in the game are all members of the imperium?

Please help.



Thanks!



I didn't find the right solution from the Internet.



References:
www.dakkadakka.com/dakkaforum/posts/list/213984.page

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