since you can't, easily buy just, a right lever, unless you pay significantly more,
as a repair part, you will have an unused left lever.. from the set.
Lots of people race on some doubles with a pretty small difference between the 2 chainrings.
so an 8t, 44 - 36 [110], or a 6t, 44 - 38 [130]
or a 44 - 39, 5t, [130 or 135] ... might be just fine..