Since Constantinople belongs to the Emperor you can not take any Units from its garrison unless you have the permission from OK. Same goes for every other settlement. You always need the permission of the person who the settlement belongs too.
Once you have taken the units you need the permission of the Megas to actually keep them. Since you don't own a Private or Royal Army all units you control once you are outside of a settlement are only there under the Megas discretion. He can abandon them at his own will.
So all things said, the only thing you are fully allowed to move right now is your avatar Andronikos Komnenos.
Cheers!
Ituralde
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