They can travel in gangs of 2-4 making it plausible for you to up the ante and have multiples attacking your party.
The baddies are chaotic evil making them lore friendly in attacking your party and initiating combat. An armour clad, weapon wielding bear creature makes a good level 2 guard and a fair challenge for several level one characters of few level 2 characters. This monster is a cool monster with potential for interesting loot.
I will be only using monsters from the first monster manual of the 3.5 edition of dungeons and dragons. These five monsters are a great way to start your campaign and to give your players a fair challenge in the initial levels.