Firstly - 20% of Ukraine taken by Russia - doubt it - looks more...

Firstly - 20% of Ukraine taken by Russia - doubt it - looks more like 10% to me !
Secnd you make it sound like Odessa capture inevitable although particularly with the carnage in the Russian fleet - not at all inevitable .

Apart from that ,what you say is possible - also far from inevitable !
Both sides are losing soldiers losing equipment and Russian losses have ben much greater to this point .
Also Ukraine being re-supplied from the west .
Because of these two things what started as a very one sided contest is more even now .

But this has become apart from anything else a war of attrition and we'll see who lasts the longest in terms of force of effective military power .

The other assumption you make is that Z will agree to a settlement if Russia does gain the ascendancy - he may well choose to fight on regardless of cost . Certainly the indication he's given so far .

F8ck what US wants !
Your true colours come out at the end of the post when you completely fail to recognise what Russia sought to achieve - biting off more land - and trying to make it sound like some US plot !
That just utter BS !
You can't logically blame an unjustifiable Russian invasion of a peaceful nation on anyone except RUSSIA !