We’ve just about fitted full size bath and separate shower, loo and basin in a 170*240 room. It’s serviceable but not luxurious. The shower is a 90cm pent and the basin is this very compact ikea one https://www.amazon.co.uk/IKEA-lill%C3%A5ngen-Washbasin-White-60/dp/B00L9NXNT2
Aside from compact loo and basin, the trick was to have the door slightly offset not in one corner. That obviously depends on whether your room layout can accommodate it.
It’s a second bathroom and we very rarely use the bath so for us so it made sense to have the bath there and a big shower and no bath in our main bathroom.
(Ironically, l have to have a bath pillow to stop me sliding underwater so with hindsight I’d have been better off with a short bath anyway.)
Having a separate shower is definitely nicer than shower over bath, but I wouldn’t recommend such a tight layout for your main/only bathroom.