I find it easier to kite Dimorph to control my Taming area. In the past, a well placed bola would easily drop them to be tranq'd. Lately my bola is bugged and doesn't work, so I had to improvise. When you hop off your mount with a Dimorph aggro'd, it will circle your mount almost too quickly to land a tranq arrow. My solution? Have your Argy/Ptera on 'Follow' and run in a straight line for a moment, turn 180* and line up your shot, the Dimorph will chase your tame, and place itself perfectly for headshots.
Get a few tranq arrows, and snipe it while it's in the air and aim for the head and fire once or twice. Then feed it 2 meat and narcotics if you need to do other things. But I used my fists so it was unconscious.