There appears to be some sort of relationship between Simba and Gi-Go. Simba’s Dreamland Tootsie pose is copied exactly on Gi-Go ponies (different head), and Simba symbols are reused on Gi-Go. Manufacturing materials look to me to be the same. Interestingly, Gi-Go also makes dolls and these are marked Simba on the head mold and Gi-Go on the sewn-in tag. (Source: eBay listings.) My theory is that Gi-Go was making them for Simba all along, or they bought molds from Simba. (Theory only!)
These appear to be by Simba due to the appearance of the eyes.
Yellow Tootsie-pose adult with birds symbol, rainbow hair:
Yellow w/ shooting stars symbol:
Yellow unipeg w/ moon and stars symbol:
Sitting Blue w/ Whistles (Windwhistler) Symbol: