Thieves' initiative mechanic is unique in this game. It allows the player to free himself from cooldown. The main purpose of cooldown is to prevent the user from spamming the same ability.
Thieves initiative mechanic allows them to bypass this without any trade-off. So in order to fix it, here are some suggestions of trade-off to prevent thieves' spamming fiesta.
This counter-part is reset if the thief gets out of fight or swaps weapons. If the thief swaps to the same weapon then it's not reset.
This change have an internal cooldown of 3 seconds (yeah this is a magic number, I don t know how much of impact it would have, but it definitively needs a cooldown).
All skilled accessed when a thief is in stealth like backstab, etc...., can reset the initiative cost.
This sounds fair to me. What do you think? (And before thieves'main complain about this, It is not a skill/trait nerf, if you re against spamming fiesta, you should agree with this proposal).