For the agro dump issue, you could try kiting the mob with JBoots. This would be restricted to outdoor zones, but you could just run away after summoning the second pet, and let it beat the mob down until death, or your pet regains agro.
If you got deep pockets, you could also get a bio orb. Just blind the mob so it will attack the nearest enemy, which would be the chained pet.
Could also try chaining earth pets, the root proc may keep the mob in place between pets. Could try using
https://wiki.project1999.com/Herbalist%27s_Spade as well if you can afford to take a few hits, see if you get the proc off.