Sorry for the late reply, but it happens a friend and I were just discussing an idea over dinner related to this thread topic, about if Loyalist Space Marines summon Daemons with Daemonology, are they still considered "Come the Apocalypse"? I agree with Charistoph, but
IMHO this is why this issue is even in question. From the Big Rule Book on Conjured Units & Victory Conditions:
Conjured units count as part of the army of the player that has conjured them...
That's from the Big Rule Book and it suggests NO, they're not even considered allies, as they are PART of the army, until you read the rest of that line:
Conjured units count as part of the army of the player that has conjured them as far as Victory Conditions and the rules for Victory Points are concerned.
I can totally see how that fragment of the quote can be taken out of context, when its point is regarding Victory Conditions specifically. We haven't had anyone do this in our
FLGS, but I agree with the interpretation, being a summoned Daemon does not somehow cancel out other benefits/disadvantages of being a Daemon, it's just that you count as part of the army as far as Victory Conditions/Victory Points are concerned.
And for this, it's because we felt you could run an Alpha Legion army better with Loyalist Marines, by representing their Infiltration skills by using Marine Scouts. Being so far "behind enemy lines", they might have stripped down Power Armour or something that made them the equivalent of Carapace Armour for saving throws, we had a few modeling ideas using, say, the Forgeworld Chaos Renegade models with some slight conversions (like putting on Shoulderpads on them). It was an intriguing modeling concept.
And the reason why we even thought about that was how the latest Marine Codex brought Scouts'
WS and
BS up to 4, same as a normal Marine. It just triggered some ideas.
The Relictors idea was also really interesting. I also thought it would with the Exorcists possibly, who actually deliberately summon Daemons as part of a Space Marine's initiation.