My suggestion: have alternative major orb crafting recipes that use either diamonds and/or gems. This allows for crafting majors with less minors but in a way that consumes these valuable resources and thus is fair to the developers. Plus, a lot of end game players are sitting on thousands of diamonds and this could be a sink for those.
The real problem is that the major orb recipes we have are aren’t real recipes but are there purely as a step towards crafting Zuul. I would also have an alt power orb recipe that uses diamonds and gems so that it’s feasible to craft a power orb from minimal minor orbs but at huge cost to diamonds and gems. That makes it only accessible to end game players but gives them a way to spend these resources.
A problem with the above is players with huge diamond hoards could craft the next Zuul-style troop the instant he comes out, but eh. The game needs more diamond sinks.