by Synegg
I like your house rules, my group does similar things but on a broader (crazier) scale.The lion is:
1) Insanely strong. Has anyone managed to kill it yet? Even 2 of the top tier gladiators allied would find it a challenge to bring down.
2) Unnecessary. When there are 2 gladiators with the same speed it is pointless playing chicken, no matter what it is just 50% chance to get first attack. This is such a simple concept and I am amazed how many people have raised this issue on the forum as being a problem.
Of course it's your game and your rules. My group has also experimented with a lion but we use it to spice things up and not to make 2 cowards fight.