Why do you feel S-hawk being weaker than S-bear is an L. Forget about agenda for once!
Yes quite frankly S-hawk seems the weakest compared to others.....
(Although they should all be relative in strength)
The other Seraphims are pretty much direct copy of their orginal with Lunarian genes.
S-hawk is the most unoriginal and would be hardest to copy from its original because it's Mihawk.
His sword Yoru can't be replicate, and it's one of the biggest factor contributing to it's overall strength.
S-shark got perfect DF suitable for him that boost his strength. But can't say the same for S-hawk since it's special case, even if Daz bones DF is perfect for S-hawk, without yoru or actual haki it won't be the same...