Force Einhar Missions for Brutus in SSF

Hello !

I´m playing SSF and have the idea to farm Brutus Leas Sprinkler. I guess the best chances are with Beastcrafting (Unique Scepter or Mace).

I have the problem that I have not enough Einhar Missions. Is there a way to force Einhar Missions while leveling? Is it possible to skip Einhar Mission in Act 2 until I´m in area lvl 28 (Brutus Lead Sprinkler) and the start new instances for Einhar. Is it possible just skipping one of the yellow beasts to looping Einhar Missions in act 3?

Any other suggestions to get Brutus in SSF?