Recently I've been seeing more people in progressive who if in a disadvantaged position will use a trade on 3, stack troops in a non-blocking position and then refuse to take cards. It seems to be more common in expert+ lobbies.
It seems to be a pretty effective technique, completely disincentivizing anyone who is going for the win to kill you (until last) as they'd have to burn troops for 0 cards.
There doesn't really seem to be much counter-play apart from if you think you won't be able to win overall to kill them before you are killed by the winner but in close games where you are trying to win this is rarely viable. Ofc winners might be kind to their opponents and kill off the stacking-passive player first, however I've never actually seen this been done in a close game.
Doesn't particularly seem healthy for gameplay as its a very low-skill strat, but at certain points it can be optimal for ranking.
Any ideas?