Here are tips that Blue gave on WGF about Exterme Herder 2.
Blue wrote:
Remember that you are faster than Balthazar.
Always pick up the petpet closest to Balthazar (unless they're too close and he'll get you). Notice that even if he's just about to grab the petpet, but you get it first, he'll turn around and head for the next closest petpet.
There is one exception to the above: if there's a pack next to the paddock entrance, slam 'em in unless one is in imminent danger.
I don't drop a petpet, ever. If I picked one up by mistake, into the paddock it goes, then grab the next guy.
Almost always go for the "freeze" crystal, and you can grab it even if you're hauling petpets. You can also run through Balthazar when he's frozen.
The "X2" is great. Since you're faster than Balthazar, you can usually get it, but don't go too far out of your way for it. You can also grab this one while carrying a petpet.
I do not go out of my way for the "fire"/fast crystal because it can make it more difficult to control Samrin and I have both run into Balthazar by mistake and been unable to get a petpet into the paddock.
Also - you can press 2 arrows at the same time to move diagonally.
Good luck!