I assume you're talking about tile for a shower floor. I have had 2" hex on my shower floor for the past couple years and no complaints. I agree with you about not using marble. Use a grout color close to the tile color.

Why don’t you like square or penny rounds?

I’d say hex over chevron
But you can do so much more than just that.

What do you think of this basket weave?

https://www.tileclub.com/products/white-recycled-glass-basket-weave-mosaic-tile-sample?variant=43481788252311&utm_source=google&utm_medium=paid&utm_campaign=20549918539&utm_content={adgroupid&gad_source=1&gbraid=0AAAAACrzUx8kBPk_Qop3ykka_gGvNOoyM&gclid=Cj0KCQjwzZmwBhD8ARIsAH4v1gVKBvoCH5ofW1VdaW2uz3wc7oZZCZ0hAcUMdIFwGbBnrmjn2M_5qWoaAiMNEALw_wcB

Terrazzo is beautiful too

https://www.tileclub.com/products/cape-beige-natural-terrazzo-sample?variant=43481722388631&utm_source=google&utm_medium=paid&utm_campaign=18133717566&utm_content={adgroupid&gad_source=1&gbraid=0AAAAACrzUx8uAtQNaizTrGxX6Mfv3pDaH&gclid=Cj0KCQjwzZmwBhD8ARIsAH4v1gUPlGjY6USAYs17rVw25pwp6yX2rqZ48uAmOKIadQ_KBsF7Ff0nKOAaAtrZEALw_wcB

Loving this as well… rock look…

https://www.tilebar.com/sample-nature-round-pebble-lombok-blend-mosaic-tile.html

What is the bath floor? What are the shower walls? what material, what size, what color.What is the shower SIZE?

Let it be noted here: A contractor who can not slope A SHOWER with a larger tile or even a linear drain? Is not one I would trust to build, waterproof, or tile my shower.

Find out every single process he uses, to create the shower floors and walls and waterproof all.

Absolute no on the pebble suggestion above. Not with your guy and most need a seal, and yes, it will be too much grout as well, even when very well done.

IMO no context gets no help. Contractors are not designers and do not get to choose tile and I assume this is the shower floor so we need to know all the other choices too.

Porcelain tiles

https://www.americanolean.com/products/mosaic/unglazed-mosaics