Does Switcheroo use only base Might for switching, or does it take into account buffs or equips or something like Rumble that applies +1 Might?

Switcheroo takes into account the current Might of the units, which includes all active modifiers, buffs, equipment, and passive abilities. It does not look only at base Might.

According to Rule 420.1 and the associated RiftJudge FAQs (specifically FAQ #6847 and FAQ #8531):

• It is a modifier, not a snapshot of base values: When Switcheroo resolves, it calculates the difference between the two units' current Might (including equipment, passive bonuses, and other modifiers) and applies a persistent +X or -X modifier to them for the remainder of the turn.
• Buffs and Equipment stay put: Physical buffs (like equipment) remain attached to their original units. They are not moved or swapped; only the final Might value is adjusted by the Switcheroo effect.
• Future changes apply on top: Because Switcheroo applies a persistent modifier, if a unit's Might changes after the swap (e.g., from a new buff, a trigger, or a passive ability), that new change is calculated on top of the modifier applied by Switcheroo.

Example: If Unit A has 5 Might (including a +1 buff) and Unit B has 2 Might, Switcheroo calculates the difference (3) and applies a -3 modifier to Unit A and a +3 modifier to Unit B. Unit A becomes 2 Might (but still has the +1 buff attached), and Unit B becomes 5 Might. If Unit A later gains another +1 Might from a new source, its final Might will be 3 (5 - 3 + 1).