No one? Bueller? Bueller?

For better or worse, the SRR editor has a 3-hire cap. However, modders can add other actors to your team which would be a way of circumventing this (you just can't hire them through the normal interface). For example, somebody could make a mod where the player can recruit some private security via a conversation/triggers, and spawn some Lonestar actors, temporarily assigned to the Shadowrunners team, to help you out on a mission.

That being said - part of the challenge and fun of the game is choosing between tradeoffs when hiring runners, and making educated decisions based on what you know about the run.

If you want a 6-man team, you could hire a mage with a decent conjuration skill (and plenty of fetish-things in his inventory), and a rigger, then use drones and summons during combat.


Final thought - possible downsides to increasing the cap:

1. Whole scale of the game would need to change and be rebalanced (but developers can use tricks like spawning more enemies in a region based on team strength and size)

2. Turns would take longer. Combat is turn-based. It's annoying when I have to wait 20 turns for my badass player character to take his turn. The wiki recommends that combat be broken up into a series of small encounters as opposed to one huge brawl.

3. Shadowrunning is illegal, and large parties draw more attention than small ones (while there may not be a game mechanic for this, it seems like common sense. Also, 6-man teams may be ok for the military, but have those team building studies been done on criminals? their goal is not 'bonding' it's quick cash..)

4. Shadowrunning is for profit, and fewer runners means fewer ways to divide the loot

(you could argue that you could pull off more lucrative missions with a larger team, but you can also achieve a similar effect by orchestrating a large heist into a series of scenarios, each working with a different team, for example, team 1: steal the blueprints, team 2: plant the charges, team 3: cut the power, etc..)