I get mob bounce when the mobs tend to move around in fights (e.g. headless horseman).
On most boss pulls though - I head in with my main, wait until the mob settles into position, and then bring the rest of my guys in. Using the Ingvar example, I start like this:
Then pull Ingvar:Code:I = Ingvar
M= Main
AAAA = alts
Then turn him around:Code:I
M
AAAA
Then hit 'interact with target' on the alts:Code:M
I
AAAA
Code:M
I
AAAA