They're growing different styles because they are grown from seed.
Even citrus that grow "true" from seed, (meaning that if the seed came from a lemon, it will make the same kind of lemon fruit as the parent tree), will see the seedlings grow at different rates from each other. Much as two siblings with the same parents will not look exactly like each other.

Trees grow from cuttings are exact clones of the parent tree and will grow pretty much all at the same rate.

I don't know much about grafting, I'll let others with more knowledge of grafts answer your other question.

They look nice and healthy, good job!