Decking Joists - Help

Hello, last year I didn’t know how to screw a screw into a piece of wood and this weekend I’m looking to start a decking project.

I’m just wondering if these https://www.screwfix.com/p/sabrefix-mini-hanger-50-x-65mm-10-pack/63868 joist hangers would be okay to use, the timber is 120x45mm and will be spanning 3m, I’ve got some twist nails to use with the hangers that are 3.75x30mm

I also have some ‘timber drive’ screws from another shop that are 7x100mm steel with a green phosphate finish.

I’ve been reading about the benefits of nails vs screws in aspects like shear strength but since I’ve already got these could I use the mini joist hangers and then screw one screw above it to connect the joists together?

Would using the screw above the joist hanger be detrimental, are these joist hangers too small for the timber I’m using could I just use 2 or 3 screws instead to connect the joists to the rim joist, thank you!

The joists are being laid on a relatively level concrete base so I intend to lay the joists on top of paving stones and then use plastic shims to create a slight fall to avoid water pooling

thanks