This is mostly true, although if you haven’t ascended and/or levelled the Troop/Pet it won’t recognise that. Also if you only need say 1 extra copy of a Pet or Troop, it might still offer you 3 or similar.
I guess it also wouldn’t work for the whole Bronze Elite Level situation (which would offer you Common troops that you already have fully levelled and ascended).
There’s was also a case someone mentioned about something like Guild War troops being the ones still required, where I can’t remember what the behaviour was (obviously not offering the GW troops, though).
When speaking about the kingdoms upgrade, 3 copies are better than nothing. Most of the time we have to buy more than we need in Pet Rescue Shop. I consider this to be a very minor disadvantage.
In general, I like the recent changes to arena and surprisingly it’s the only game mode I really enjoy at the moment.
It is possible to reduce the award options/offers from Arena.
If you have all kingdoms and pets and troops where nothing can be offered. I’ve not had any of those since Arena changed. So no wasted offers. All kingdoms nearing a new level, all appropriate troops medalled. Pets no offers. The trick with them is to stall a kingdom if you are a couple of copies short of a kingdom req.
Example leave glory troop TIL maybe Sunday. Albeit can only think of Wimp where that happened and it was before Arena.
So yep get zillions of useless offers but generally get a deed offer maybe 3 times a week. Not much in way of imperials.
I may be alone in this, but I only buy the pet offer if it gives me enough copies to ascend and power up the kingdom. Otherwise, I don’t bother, and prefer keeping my gems.