Spaying incision length

Hello,

I had Daisy spayed today; I was shocked at the length ot the incision
(about 4 inches) and now wonder about the credentials of the vet.

I'm really upset about this and blame myself for maybe not asking
enough questions about the surgery beforehand.

When I adopted my first 2 cats the SPCA spayed them before I took them
home. Their incisions were only about an inch long and I didn't have
to take them back to have stitches removed.

Are there different surgical techniques that explain the disparity?

Thanks.