Edit: capx fixed
since there was some talk about different kinds of enemies, but no actual project with that feature except for the Space Shooter (or I am blind), I went ahead and gave it a shot. I am a beginner, so it really caused some meltdowns in my brain during the last 3 days and there's probably still a lot of room for improvement perfomance-wise.
As I am working on a tower defense with several levels, I made it so that each level can have its own .JSON-file where the data for the Enemy-Wave-Management can be stored and fed to an array which the events have access to. If you double-click on the JSON-file, you can easily access and change it. (It opens with your standart software. I use JSONedit.):
I probably could have saved some events, if one were able to address members of families or instances of an object that have a certain instance variable not only in conditions, but also in actions, somewhat like this:
So all in all I think it works but again, since I'm new to this, if someone doesn't find it too complicated to have a look at it, knock yourselves out.