Why is Marcus Corvinus's hybrid nature different from Michael Corvin?

I found this on Underworld Wiki page about Hybrids:

There are different types of hybrids in Underworld series:

Lycan dominant - Vampire hybrid:

A Hybrid with a Lycan dominant side resembles a Lycan in appearance. However, their faces are only slightly elongated, and their eyes are completely black. Their rib cages are also slightly extended. They have little or no fur and blue skin. These Hybrids have the talons and animalistic posture of a Lycan. They also possess the Lycan's signature roar. Michael Corvin is the only known Lycan-Vampire Hybrid. It is immune to silver and sunlight. These Hybrids must also feed on blood, like an ordinary Vampire, becoming ill if they consume ordinary food.

Vampire dominant - Lycan Hybrid:

A Hybrid who was a Vampire first, on the other hand, has more physical attributes portraying its chiropteran 'ancestry'. While it shares the black eyes, grey skin, Lycan talons and musculature of a Lycan-dominant Hybrid, a Vampire-dominant Hybrid has noticeably bat-like ears flattened into its head, a bat-like nose, no hair at all, and taloned, retractable wings. Marcus Corvinus is the only known Vampire-Lycan Hybrid. However, as Marcus is the original Vampire and the strongest of his kind, it can be speculated that not all Vampire-Lycan Hybrids have abilities as potent as those of Marcus. Any effect of silver and sunlight might have on them is still unknown.

Here is the info about two hybrid types you asked for.
Note: There are several more hybrid tipes in the series, you can find more about them in the link I provided.