1) Reputable

They need to be 100% trusted. People don't want to risk paying money to people who will flip sides if the money is better

2) Professional

People also need to know that if they don't keep paying, they will lose their services. If A is paying them to kill B, and A stop paying, they will happily work for B if they want them to. That's the deal. You pay, they play.

3) Effective

They will of course need to be worth paying. They will need plenty of mercs, with the right mix of specialisations, both in SP, and player skill. People need to know that when they pay them 500,000,000 ISK for a planet capture, they will get the damn thing captured. Win rate will be important.

This also means that for top tier merc groups, they will need to have EVE players, because orbital bombardment will be important. Maybe the client can serve as the support for some conflicts, but people will pay more to have you do it 100%, if you can, and that means more profit.

4) Not infested with spies.

If I have a secret plan to capture planets from someone, last thing I want is for them to know the plans before the attack, letting them get their mercs ready to defend. Maybe even letting them know what we plan to attack with, so that they have the exact counter ready.

You may say this is "childish", but that's a mistake. In New Eden, spies can make or break a fight. When we are in fleet fights, we often have people in the other fleet, sending us info and plans from the enemy. This means we are ready for what they have, what they are doing, and can even be where they are going to be before them sometimes.

New Eden will be affected by spies, in the black, or on the ground, whether you think it is "childish" or not.

5) Simple to deal with

They will need to have a good team managing contracts, PR, relationships, logistics, and intel.

A merc group lives and dies by it's contracts. Sometimes, jobs will come in with fast turn around time. They will need people to create and agree to contracts, and get the assets on the ground in time for it to matter.

They will need people to manage all the people they know, and offer contracts to them, if they see the might need some help. They will need to manage intel, knowing who is fighting who, and what is going to be the next big conflict area.

All of this will require interaction with outside entities. Complicating things with "spawning genome" is just making things more complicated than they need to be. If you say "recruitment officer" people know what you are talking about.