Sorry, i decided to board you, as you board everyone around It was expensive tho

I know that boarding is fun, as there is no risk of loose if you have enough hp
But, how does it looks in game...
I have ship with 1b marines. Someone board it with 500mil marines. Ummm, not enough. Ok, again, still not. Oh, i boarded same ship 5th times and now its mine *
So if my marines completely fail, attacker ship captain said: "Ok, we have lost, close the door and we will go now", and defender captain said: "Oh well s**t happens, try again in a few minutes".
No. Defender marines should enter attacker ship and take it, as there are lots of them
There should be risk of loosing ship if you fail badly...
* No powerships

Is there any use of def in superships? Ie. in missions where there might be up to 10 fleets vs 1-2 superships?