Teambuilding RoboFortune

Robo doesn't benefit much from Squigly or Ms.Fortune, but I can see both of them benefiting a lot from Robo's assist (Beam) just because of how good it is.

Robo can benefit from Valentine because Valentine's heavy bypass assist lets Robo convert from far away beam hits and get consistent throw conversions from ground throw via L Beam + Bypass right before they touch the floor.
Bypass also lets Robo build heads mid combo with cool routes like this.

But in a duo, Robo needs more than Bypass and Valentine needs more than Beam imo.
I think Robo in a duo is best with something to use as a defensive option because hers are weak once the opponent starts pressure.
(L Bomber, H Brass, M/L Beat Extend, Pillar, Updo, H Chair Toss... are good options).

Moving into a trio, I think the above assists + one fully horizontal assist to compliment her zoning from a distance OR an assist to compliment her resource building like A-Train or Excellabella (Where she can call 3 heads during them) would be optimal trio set ups.

If you take H Brass, it gives zoning confirms, more space control during zoning, and it also is a good defensive option so I think it's the most optimal assist to take for a duo.