I'm looking at putting one of these on the side of the garage in back on existing concreate to park an additional car, boat, etc.

The structure would be in the corner of an 8 foot fence and the side of the garage. Therefore, I would not expect much high straight-line winds. While I know it would best to sink the post into the concrete, would it be OK to simply anchor the structure into the concreate with quality materials and workmanship?

Norwood 20 ft. x 12 ft. All Cedar Wood Carport Pavilion Gazebo with Hard Top Steel Metal Peak Roof and Electric, Brown

They make a taller anchor

Also do not use lags use bolts that go thru post and it will be sturdier. Even tho only two one on top and one on bottom of the other side

Last 5/8 x3 1/2 or 4 concrete anchors

Use theses

https://www.strongtie.com/standoffpostbases_castinplacepostbases/mpb_base/p/mpbz

I think it would largely depend on the thickness of your slab + weight of the structure. I just had a similar patio cover built in Denver and my footers are 18" diameter and 4' deep.

Slab is 4" thick.

I built a free standing 20x14 pergola on a 4" pad with this. Braced appropriately it has been up 7 years here in Dallas through all our storms successfully.

https://www.strongtie.com/retrofitpostbases_postbases/aba_base/p/aba