Besides the previously posted Super Duos, there are a few recognisable 'Teams within Teams'; pairs or trios of Supremes who naturally work better when played together.
The rules of these 'Mini Teams' (for want of a better tag) may offer mutual immunities or buffs, or both. And while they may not have the Super Duo Trait benefit, they still have advantages if used in the same larger Team.
Taking Gemini X and Gemini Y as the first pairing to look at, one glance at their Team Powers strongly shows that they are intended to be fielded together. One tricksy thing to consider is that the 'shared' Damage is that a total of 10 Damage can be taken while still leaving both in play; what about using one withdrawn from the other to limit incoming damage (Blasts, Rays) while making best use of this benefit? With blocking and healing opportunity-creating Actions (Gemini X), and area and Close Combat denial Actions (Gemini Y), they can be used to help shield you other Ulthar, or even potentially to hold objectives.
I cannot claim to have mastered these guys - in fact I struggle with Ulthar for some reason (I think it takes a while to get a good 'handle' on the Ulthar Sub-Faction), but if viewed as a small countermeasures type of unit rather than two (fairly weak) Level 1 Supremes, that may go some way to explain how to hopefully best utilise them.