Manhunter grandmaster
LEADER OF THE MANHUNTERS: After Manhunter Grandmaster resolves a non-free action, you may give any number of other friendly characters with the Robot keyword a free action to move 1 square. If those characters are also named Manhunter, they may move 3 squares instead.

Sentinel Mark V
COORDINATED ASSAULT: Once per turn, when another friendly character with the Robot keyword hits an opposing character, Sentinel Mark V may make a close or ranged combat attack against the hit character as a free action after actions resolve.

Can I choose the order in wich these 2 traits would interact?

As the active player, yes you get to choose in which order to resolve effects that occur simultaneously.

So yes, depending on the click, you could either move away to Psyblast, or move in for CCE

I don't think the Mark V would be allowed to CCE or Psy Blast. CCE requires a power action and PB requires a ranged combat action. The Mark V does have the ability to decide to either shoot or punch the hit character though.

Actually he can use both just fine.

CLOSE COMBAT EXPERT Give this character a power action. It makes a close combat attack against a single opposing target character; modify this character’s damage value by + 2 for the attack.

PENETRATING/PSYCHIC BLAST Give this character a ranged combat action. Damage from the attack is penetrating damage.

ATTACKS AND ACTIONS
It’s important to understand the difference between actions and attacks. Some game effects can be used or triggered only when a character is given a particular type of action. Combat actions, for example, will always lead to combat attacks,

CCE is a power action that grants a close combat attack. P/PB is a ranged combat action, and ranged combat actions are always ranged combat attacks.

The Sentinel can't use CCE or Psyblast with Coordinated Assault for the same reason people can't use CCE or Psyblast with HSS.

CA doesn't grant any kind of action, just an attack.

Those two powers make a nice combo. Robots are cool!