That's about the size of it, yes. There's a reason for the Wealth By Level guidelines, and this is half of it. At 9th, they're supposed to have about 36k in useful equipment each. That's, oh, a +2 armor and weapon for the Barbarian, as well as +2 Gauntlets of Strength, a +2 Vest of Natural Armor, and maybe a +2 Peripat of Health, a +2 Cloak of Resistance, and some potions. That's 4 points of AC, three points of attack, three or four points of damage, and 9 HP, plus the possibility of Flying, being invisible, or self-healing in combat.
That said, a Sorcerer, Cleric, Druid, or Favored Soul (Wizard works, but is harder to keep under cover, due to the spellbook requirement, unless secrecy of abilities isn't needed) with some decent buff and combat control spells could have very easily turned that encounter around. Magic Vestments gives everyone with clothes and/or armor +2 AC, Cloths and a Shield +4 (Mage Armor gives +4 Armor to those without any yet). A little Shield of Faith spam just before the encounter (it was an Arena bout - it's not like they didn't have warning) grants the entire party +3 Deflection. +5 to +7 AC to every party member - suddenly, those Lions can't hit worth much. Bear's Endurance, Bull's Strength, and Cat's Grace do wonder's for HP, attack, and AC (respectively, for the most part). If secrecy isn't important, Web, Wall of Stone/Ice/Iron/Force (as appropriet to the area) can be used to prevent Pounce from coming into play.
Edit: With five people in the party, you could have had four Tower Shields, a corner to fight from, and one guy with a bow. Tower Shield guys use the Total Cover option, which makes it so the lions can't attack them. They still block travel, so the guy with the bow can stand behind them, shooting the helpless lions to death.
