So we are getting hardwood floors. Not engineered but hardwood. Seems like we've decided over unfinished vs prefinished although I've read prefinished holds up better to scratches etc...heard prefinished comes with some issues.

Any advice as to what my floor guy can do/add to the floor stain to make it hold up better to a dog and kids?.

Were getting white oak.

Thanks a lot

If you can find the color you like the pre-finished flooring will usually hold up better than finished on site.. Claw dents from big dogs are not really scratches. If you look straight down on the "scratch" it doesn't look like a scratch, but it shows up in a reflection. A finish with aluminum oxide and multiple layers resists scratches going through the surface. Use furniture protectors and keep grit from getting in the house to protect from scratches. Don't try to slide anything across the floor.
Some pre-finished flooring has a 50 year guarantee against wearing through.
The main detraction of pre-finished flooring is the micro-groove. The edge of the floor strips are just as smooth as the face, so it is very easy to clean. The reason for the micro-groove is to prevent splinters in case an adjacent board is not the exact thickness of it's neighbor and a square edge will have a chance of splintering if something is slid across the surface.

So flooring guy is telling me that pre finished may give me unevenness where some of the boards meet if my subfloor is uneven. He's telling me to go with prefinished.

The directions that come with pre-finished flooring specify that your sub-floor needs to be flat. There is a recommendation that your floor be flat with variation of less than a quarter inch in 10 feet. This is something that a good floor mechanic can remedy if your sub-floor is out of specification. This is important if you value a warrantee. Check the floor with a six foot level as a straight-edge. Don't go by the bubble to check for level. Sand high spots down and build up low areas with layers of thick tar paper roll roofing. This is what I do for pre-finished or unfinished that will be sanded and finished on the job.