Is there a better way to jumper 3 terminals together?
I always use DIN-Rail terminal blocks that have a bussing feature across the top so that I don't have to double up on the wire entry connections.  Different manufacturers have both pluggable and screw down bussing arrangements.  As an  alternative to what you show in your photo, you can buy a comb bussbar that joins more than two at a time.  Buy a 10-position bussbar and then cut to length for less than 10.