followers got no set like you have (or lon), no convention, no traveller/compass, focus/restraint, other multipliers from passives, skills or items, leg. gems, .... the list goes on...
your follower does absolutely no dmg, trust me. it's not 1/15 more like 1/100,000
and on top they mostly attack with no skill at all (base attack)
go for IAS and CDR with the proper useful items like mentioned in this thread