Special ships

Hey, i randomly got an idea for the civs that sounds really cool for me at least.
I was thinking of a mechanic for some unique ships with two health bars or a health bar cut it two(uneven). So when the ship takes X amount of damage then the health bar is decaying, simulating sinking. So ur had a fight and ur still good for a few more seconds being more tankier than the regular ships but the ship will inevitably sink if it reached a critical level of damage.
Tehnically u could add that even for land units if u switch sinking with bleeding.
I was just wondering what will the community think of the idea, and u can do the balancing urself

Sounds like a very interesting mechanic but rather for newer Aoe games.