Except… I’m pretty sure they actually do check collection. About as sure as I can be from my own experiences with four accounts and anecdotal evidence from the forums without having to do large scale data gathering effort.
I’ve never gotten a troop offer for a troop I currently have at mythic, and I have multiple kingdoms across multiple accounts “blocked” by not having enough troops leveled high enough. When the slot 2 offer is a troop offer, I always get something out of the comparatively small pool that I haven’t fully ascended but are still offer eligible, usually something I forgot to ascend after getting enough copies from a recent event, or a newer bounty troop or slayer troop I never got all the way up. I have a ton of troops ascended but at level 10 and a ton of kingdoms that say I need more troops at level 20, and this pool of troops never seem to generate any offers. The chances of me having not seen a troop I already had fully ascended are at this point infinitesimally small, considering how often I get an offer for a troop because I intentionally slow level my kingdoms. At any given point, I have lets say 10 or more offer eligible troops in a kingdom fully ascended, and if I have a missing power requirement for leveling additional troop to 20, the offer will invariably be for one or two offer eligible troops in the kingdom I haven’t fully ascended.
Statements above seem to indicate that the check for having a troop be legal for an offer will consider if it needs to be medaled. In other words, if the requirement being checked is “Upgrade 22 Mist of Scales troops to level 20”, and I have a mythic ascended Scale Guard, I’m never going to see a Scale Guard offer. Under the current system. It already does this. But if I progress the kingdom far enough for “Upgrade 5 Mist of Scale troops to Elite Level Bronze”, as per the original post, they will start giving troop offers for troops already at mythic, as if having more copies of this troop will somehow contribute to the requirement for leveling them to Elite Bronze when they are already max ascended and level 20. This is out and out incorrect. A check is already taking place here. The check being applied is the wrong one and/or for the wrong offer.
This bug report makes it even more apparent, because if there aren’t any eligible slot 2 offers available, slot 2 is instead a random slot 1 type, and a ton of players were at this point for some length of time already. And also why these reports are from Mist of Scales, which is currently to my knowledge the only 21+ power kingdom, which are the only ones with elite level requirement. The “not achievable yet” is a different issue that has come up a few times in the past, but to my knowledge this has never generated offers for more copies of maxed out troops. (but also it shouldn’t be a thing, because again, collections are checked)
It should be noted troop offers, ingot offers, and pet offers appear to check different things. Some of these other checks are known to be “shallow”, for example, getting ingot offers if you have a collect x weapon requirement, or a fully level x weapons requirement where you don’t have any more weapons in your collection to level, and the type of ingots may not correlate with which weapons, if any, you need to level to overcome this battleneck. There are also reports of fully ascended pets being offered if they aren’t fully leveled yet, but having a fully leveled fully ascended pet in a kingdom where the requirement two level 20 pets does not appear to trigger any offers for the pet that is already fully ascended and leveled. On the surface, these are examples of “not checking the collection”, but really they just are checking simple criteria within the collection. “Level a troop to x” checks if is ascended far enough to do so and if so removes it as an eligible offer “level a pet to x” checks if the pet is already leveled that far and if so removes it as an eligible offer, etc.
tl;dr:
If medals aren’t possible as a slot 2 offer, then getting elite levels on troops as an uncompleted requirement shouldn’t trigger any offers to take place. Right now what appears to be happening is the game is using missing elite level requirements to check for “more copies” troop offers, with the secondary check being any troop not at least that specified elite level (out of the greater eligible set) being eligible to trigger said “more copies” offers.
I could be more sure with a large data gathering effort, but in this case “proving it doesn’t actually work that way” doesn’t even get us anything tangible, it’d still work the way it does now for whatever reason it actually does and then the issue would have to be raised again to (maybe) just get a better explanation of why it actually works this way. Instead, I’d like to ask @Kafka to please check with the team about this. If you are at a point in kingdom star progression where needing elite levels is an uncompleted task, this should not trigger offers for getting more copies of troops you haven’t elite leveled yet. Since there aren’t appropriate slot2 offers to progress elite level, this should not trigger any slot 2 offers. Whether or not collections are actually checked and to what degree, missing elite levels as a kingdom power bottleneck should not be a criteria for any slot 2 offer.