Tumbled marble might look out of place if it's the only natural texture in the room. If you want to keep a similar contemporary mosaic, then 2 things for you; Firstly, measure for yourself the actual mosaic sheet - don't take the written dimensions as gospel. Secondly, once you have a couple of favourites in mind, take a look at tile trims to incorporate with the mosaic. Remember, you can cut the mosaic sheets into thinner strips. Trim could be square edge tube style trims or even L shape angle in either aluminium or chrome and can be used at the sides of your mosaic or, in the case of the angle trim, used in multiple vertical lines running through the mosaic. Knowing the dimensions you have to play with will make it easier to design a solution that keeps grout width to appropriate size of 2-3mm for wall tiles.

I was taught to always have the cut tiles at the bottom.

just realised that my suggestion has overlapped with Dr Retro and i agree that you should be able to have (from left to right) a 900 wall cabinet with three equal doors, a 900 wall cabinet with the 900 wide rangehood and three equal doors and a 600 wide wall cabinet with three equal doors ie 8 x 300 wide doors with the left hand side of the range hood wall cabinets lined up with the 900 corner cabinet BUT is there any special reason why the wall cabinet for the rangehood was suggested as 1000 wide?? if so, the same concept applies ie left hand wall cabinet would be 850 wide with three equal doors, 1000 wide range hood cabinet with three equal doors, right hand cabinet 550 wide with two equal doors..ie 5 doors about 270 wide and 3 doors about 330 wide above the rangehood but aim for the 8 x 300 doors.. the cabinet maker should allow for all the necessary clearances and fillers to create a uniform appearance

Proportional consistency - keeping the 1:2 rule in place everywhere will jar less than having the same architrave but varying the skirting. If you’re already considering 90 and 140 skirting, why not go for 40 and 70 architraves? The effect will be more harmonious and it shouldn’t impact the price too much ... plus, it’s your house - if you like the 1:2 rule then use it :-) (PS: if it does impact the price too much, just pick one size of each and save more cash)