I have a little thing that feels uncertain when it comes to reinforceing areas on a planet and attacking an area on the same planet you reinforced.
Lets make a scenario.
Player A has a base and two units in a zone on a planet with a total of 2 zones. On the other zone, Player B also has two units, and the area can contain one more (to a total of 3).
Player B resolves a mobilize order on the planet Player A has his base on. Player B has a transport to this planet and decides to make the best of the situation, to reinforce the remaining slot and attack Player A's base. Player A has an anti-air module making it impossible for B to make a straight-on attack on his base so he will need to take the long way.
So the question is, can Player B attack with his 2 units -AND- move in 3 new fresh units on the zone he occupied? Does all moving happen simoltaneously? (sorry for misspell)