i just imported the dota2 model in blender and looked at what weights were assigned in weight paint mode. One problem i do ususally see is that the mesh you make will assign full weight to the "root" vertext group when you parent it to the bones of the hero model. Just make sure it isnt assigned to the "root" vertex group unless its supposed to be.

So I took your advice and learned how to use the weight paint tool and It pretty much solved my whole problem. It was a bit confusing to learn and require a good amount of guess and check but it worked. Thx for the suggestion! Now I know another obscure tool in blender that will save me ass loads of time in the future!

Ok thx. i appreciate the input. I guess ill keep fiddling with it.

So I watched and followed the second tutorial that was posted for the Dota2 Workshop and got through every step except the rigging to the bone. Im trying to make a set of shoulderpads for omniknight and there is one mesh which I want to rig to each shoulder but there are no specifications or guides as to which bone or bones im supposed to parent the object to, and It also seems blender wont let me parent to a bone if there are multiple bones connected to the one im trying to parent to. Any suggestions?