Should human/vampire hybrids in Twilight have been just as strong as Newborns in Twilight Saga?

The difference between the hybrids and the newborns is that the hybrids are hybrids and not newborns.

Newborns are full vampiros filled with human blood.
Hybrids are only half vampiros filled with human blood. They are half human, and blood is not what makes a human stronger. A human with extra blood doesn't make them stronger than any other human.

I don't see how it would make sense for them to be the same.

No, because the Hybrids are only half vampire, not full vampire. Their human side gives them más weaknesses and dulls their vampire abilities. The difference with the blood issue is that vampiros use the blood that remains in their body as energy, which makes them much stronger than normal vampires. The blood in hybrids is needed in their arteries and veins to provide oxygen and remove carbon dioxide in their cells, which respire where a normal vampire does not. In short, they use the blood in their bodies for human functions whilst the vampiros use it for pure energy.

No, but there is one hybrid who was born to a newborn father and a human mother. Her name is Lenna but she isn't mentioned in the libros o the cine but she carries extra strength from her newborn father and it will stay with her until she stops growing so i guess thats the closest thing tu can get.