I may agree, yes. Unfortunately, I think it will be hard to balance for all levels.
Not sure what defines all troop slots, despite AT lvl and connecting to fb but for example:
Players in middle/low trophy range can still be players whose level/items/spells/troops are in theory too high for that trophy range and players who have access to many/all troop slots. It is also not a problem to have friends with strong/max troops who will be willing to donate them. So in this case, yes, I agree that such players will have a huge advantage.
However, from my perspective it looks a little bit different. Note that I do raid with mummy which I think is OP and makes my raiding way easier. I can beat top 10 bases thanks to that mummy, without even using insta troops, however if a raid goes wrong I do use it - so I said mentioned in previous comment, I cannot yet tell if those insta troop makes my raiding easier or just a mummy.
Though, on the point where I am now I find those insta troop quite essential. I’m a player who likes to raid top 10 bases, not only top 10 but basically all top, strong bases out there, before previous update with many forges I could challenge myself trying to beat those bases, I could win using my skills, I could lose but after 10 tries I could beat certain bases - also it was a challenge with constantly changing war boosts. After the update, some top 10 payer forged their bases extremely and now the skills I have are in 99% cases not enough to beat such bases, I can try 100 times but still will die not reaching 10% of a base. Again, I may do better or worse depending on war boosts but still cannot do much against forged defenses. So in my case I do like those insta troops which I think is the only way to beat those bases (the only way inspite of scrolling).
However, it also depends what attitude players have for those insta troops. Personally I prefer not to use them and raid as I would always raid but sometimes when a raid goes really wrong I use them. If I win a base using one or two insta troops, actually I feel bad about it as I would prefer to win without using them (I hate scrolling and those insta troop are to me a kind of free scroll, a scroll that opponent won’t seethat I used it but I know I used it and hate the feeling of it). Though, from observation in my alliance for example, I can see always the same players asking for troops and they do it quite often- as, in my opinion, they rely only on them, use them without thinking, without trying to challenge themselves, without trying to improve their raiding skills so yeah, I can see your point.
This will be a very complex issue and for sure will need some balance. They can be useful at certain trophy range and OP in another, some player will use it as a backup plan in really hard situation, some player will “abuse” it and use every raid, from the start of the raid to the end of the raid.
Personally I was suprised by only 2 hr cooldown and I thought it would increase in time, trying to prevent players for using it too much, too often.