I think! I have a habit of overplanting plus bought some new, to me, plants last year that were taking over my small garden. Anyway, I got rid of the thugs and re-arranged things so, hopefully the shorter stuff is in the front and tall in the back. Now I just have to re-mulch it and hope everything lives. Oh the thugs are Purple Dome Asters. Gorgeous plants but they went from a 6 inch pot to a 3 1/2 foot wide plant in one year and had runners growing into flowers a foot away! I just don't have the room for that sized plants. They were beautiful though.
It sounds like you have things arranged properly now. Purple dome asters = thugs. hahaha. That's a good one. I know exactly what you are talking about. Some asters are more bullyish than others, but generally I find that one has to keep close tabs on asters in general. Those Purple Domes really are lovely though, I agree with that too.
Many popular garden plants are thuggish to me. I don't like to spend time with the shovel after planting anything. Good for you for taking control and getting it like-you-like-it!
I don't mind what I call 'polite' spreaders. That's the ones like tall sedum that I can cut in half with a shovel, remove half of and leave the rest in the ground. It's the ones that the roots spread out and new plants are coming up a foot away, generally in the middle of another plant, that I can't stand. No matter how pretty they are.