Technically, yes. You can use whatever armies together you want. You could use units from every army into one mega army if you wanted to. However, apocalypse is meant to be very narrative driven, and I doubt you'd be able to justify using those things together. It's very unfluffy :P
If you're just having a friendly game with your mates though, you CAN do it as long as no one else has a problem with it.
The ally matrix basically gives tells you how hard your imagination is going to have to work coming up with ways to have them fight together.
For instance, Eldar and orks have a dark marker signifying they'd probably never ally. However, you could represent this in a different way. You could take some inspiration from dawn of war and say that the eldar lured the orks into a position where the battle was going to take place. Then, use say the "flank charge" strategic asset to represent orks entering the battle from behind the enemy as they heard all the fighting and were eager to jump in. |