Can't really figure out why you've bought a pack of 3? if you think 2 may be all you need?
(These aren't one of those 12v downlight sets that come with readymade lengths of plug-in leads that go from lamp back to the driver.. and/or don't give you the option of only using 2 lamps?)
Do these light fittings have built in lamps or are they just cans with removable GU10 LED's?
If they are removable GU10's then you can get a heck of a lot of light variation by selecting lamps with varying; Lumens.. Colour intensity e.g. warm cool, where more Kelvins=cooler..
and Beam angle, many GU10's are approx 40degree beam angle, but 60's 90's 120's etc.. can be found..
So a higher lumen plus wider beam angle will give less shading issues.
Our downstairs loo is 1200mm x 85mm that has 2x GU10's plus a fan in the ceiling..
If you've got the lights and the lamps are removeable..
you may as well just fit all three to start with as you can always put lower brightness lamps in if you find it a bit too over the top?
If they are light fittings with integrated LEDs with no replaceable lamps...
Don't fit them.. send them back & get a refund..
Then buy some with removable lamps!