The icy veins guides are run by the top top hunters so yeah, great guides.
MM isnt really meant for pet use and certainly not for multipull pet usage. Lone wolf the talent that removes the pet form MM is a huge damage boost and lets you kill mobs quickly without a pet. Your issue is that a MM pet cant really hold aggro when you're hitting for such high damage.
here are a couple macros that might help though, i use them to let my pet tank 5-10 mobs at a time, hit the macros then multi shot.
Macro1 : Focuses your pet so you can quickly target your pet with the other macro
Macro2 : Misdirect your pet, this can be used as a mouseover macro if you prefer, both built in
Personally i'd recommend BM for levelling to 110 though and switch-over then if you prefer to play MM.