If you want to build around your mage's abilities, play the Straywood Beastmaster. If you want to run a build that doesn't care about Quick Summoning, Battle Skill, or Melee +1, then play the Johktari Beastmaster.
I'm working on a Johktari Beastmaster build that runs Steelclaw Grizzlies, Dire Wolves, Galador, and Tarok. The idea is to play creatures and buff them, while staying out of the fray as much as possible. In this style of play, having Fast innately is nice; initially it helps me pressure my opponent faster while still being able to do some buildup. Later on, I can cast Mongoose Agility and start running away from my opponent. Wounded Prey is free bonus damage if I decide to kill one of my opponent's creatures (and they happen to be Living). Pet isn't nearly as efficient when you don't plan to stay in the same zone as your Pet regularly, I don't want to play level 1 creatures in this build, and I don't want to get close enough for Battle Skill to help. I don't use Archery, but I still expect to get more out of the Johktari BM's abilities than I would out of the Straywood BM's abilities.
On the other hand, if you want to swarm, even if you just want to swarm as a side project, play the Straywood Beastmaster. Also, if you want to punch things, play the Straywood Beastmaster. If you don't want to do either of those things, or if you want to use a bow, play the Johktari Beastmaster.