Looking for help with my UA Ranger Beastmaster

Context: I started at 3rd level with a dual wielding Stout Halfling Beastmaster that rides a wolf into battle. Currently have a Rapier and a Short Sword as my main sources of damage.

We just hit 4th level and I had originally planned to take Mounted Combatant as a feat. My DM interjected and brought up some good points about maybe taking Dual Wielder as a feat as it would enable me to wield a 2nd rapier, have a slightly better AC, and make it easier to swap between my two weapons and my optional bow.

Looking for some external feedback as Mounted Combatant allows me to take hits for my wolf, and he would gain be able to negate or halve the damage on dexterity saves. It would also enable both to have the same initiative, and the wolf can do a move + Dash, Disengage or Dodge.