Sunny is prob like the most durable ship in the series.
Zoan King is physically stronger than Marco indeed, Marco needed a technique(shockwave) to match what King did physically.
But non of them is close to BM level in term of strength, King doesn't even look like he's stronger than Queen physically, since King's beak charge barely got past RS Sanji's defense, and Queen got destroyed by BM physically in a direct confrontation.
Marco is even weaker physically, Marco got instantly choke grabbed by BM due to vastly superior strength, can't even resist. BM's attack KO'ed Queen, not like for good, but still a KO, like Kaido's Ragnorak KO'ed Luffy briefly, much more damage than Phoenix Brand, which Marco used as a surprise attack, AND it interrupted Queen's beam, causing it exploding in Queen's mouth, which prob caused extra damage.
YC's physical strength doesn't cap at very high level, Queen and King already seems to be close to the threshold(specially Queen, who seems to have a more strength catered DF), only one might be stronger than them is prob Jozu, who can throw an iceberg bigger than Sunny, but can't even break parasite.
Like Jinbei has more strength feats than all YC's actually, can hold his ground against BM physically, for a bit, the rest just can't compete at all.
Physical strength wise:
BM > Jinbei > Jozu/Queen >= King > Marco