Spanish pinball history source here
What do you want to know?

Generally speaking these companies either had the same owner or later in adopted employees and staff from one another resulting in generally similar machines and designs in both hardware and mechanics.
It's an overall wild mix of Gottlieb and Bally tech, or looking at inder/spinball more of a data east like approach.
Stargame/Cirsa were importing Williams Games and their own games are very similar to Williams machines.

What game have you bought BTW?

I can't help you with that question (contactable ex employees)

But yeah they share similar lineages I think one of the most important people in spanish pinball history is Juan Pareses who founded Petaco/Recel.

I think his last endeavor in pinball before he died was Juegos Populares if I don't confuse his name with Eulogio Pingarron.

All in all they either bought out each others assets during the late 80s and 90s or just faded into the unholy abyss of manufacturers who had to cease Operations.

It's a more complex history than the American one as the spanish pinball industry originated from importing American games and gathering knowledge and making things better other than just keeping shut works and recycling that for decades (e.g. the spanish pinballs all have either plexi over the PF of nearly indestructible clearcoating)