In our supers Fate game, the PCs occasionally join forces with NPC heroes (also shadowy government agencies/morally ambiguous villains/etc.), a genre staple: team-up. The problem is, I don't want to be rolling dice for and against myself, especially if there are multiple NPCs involved, as that means players are just watching me play with myself for a few minutes before moving on to their turn, and I'm not really into that. One option for circumventing this that I've used in other systems in the past is to have the allied NPCs be useful elsewhere, fighting their own battle that I narrate. While simple, it's not very satisfying either as there's no interaction between this other fight and the PCs.
Is there a trick of a Fate fractal to have NPC still participate in a conflict and interact with PCs (perhaps by creating advantages?) without hogging the spotlight and GM's time, with the possibility for a zoom-in into full conflict rules should PCs wish to join in?