General observation:
Don't forget to use your powers of narration! But don't overdo it either
Maegon is doing it right ATM. He tries to bring in some loyalist reinforcements to help with the xenos - I hasten to add that I initially planned for only one xenos fighter to attack again - so you can blame him for the other two
If the GM thinks that this is too far-fetched I might rule it was a waking dream or enemy disinformation. On the other hand I might think its cool and have an entire company of Ravenwing appear! Or maybe just a one sergeant and a few other astartes, plus some other survivors (effectively a warband!).
If Nouri wants to be away; narrate him awake. I haven specifically ruled him out cold. And even if I did he could wake up! On the other hand you might want him to stay down. Point is: Use your narrative powers Alan!
Some with Azrael. Put four squads into the ship and narrate...tell the tale of how they manage to locate the command centre...but leave some leeway for me to embellish if I think the level of the opposition is too weak (for example).