I'd have to guess that Red Giant Entertainment is the flagship company. They should share in the common goal. Since Isen & Aimee are on the Red Giant "Entertainment" board of directors, they in essence work and profit for/with REDG, IMO.
I haven't seen Magika, for example, under the Red Giant Media name. But recently it lists Kevin Fox as the producer (from Red Giant Media). Before it was (and probably still is) owned by David Campiti and marketed by GlassHouseGraphics as well as Red Giant Entertainment.
Perhaps this is a case like Lexus: where we all know them as "Lexus" but it's still owned by "Toyota".
$REDG