To give a visually balanced & pleasing look, should the shower/tub combo tile grout WIDTH be the same as the bathroom tile floor grout width?

Bathroom Floor Tile:
• 24 x 24” square Slate tiles
• pattern placement of tiles: grid
• Grout width: 3/16”

Shower/tub Combo Tile:
• using rectangle 2 x 8 tiles
• most likely pattern placement of tiles:
stacked horizontally
• Grout width: ???

Apologies, no image references because currently everything is gutted.