Any combination with Lesser in it will be capable of producing BELs. If all you care about is hitting a BEL and doing it on the cheap, then yes just get any Lesser. But if you really love the Lesser gene and in addition would like to produce BELs, then pic an animal you just can't live without, that also carries Lesser in it. You can still hit BELs. If they carry the other genes then it is a bonus.