Quoting AngryZealot, reply 22Erebus has a distinct advantage at level 1 vs Regulus (or any other demigod really) because he can get 2 bites in. That's 600 extra damage and 600 extra health -- a 1200 damage gap that the other player has to close. Level 1 isn't a very fair comparison.
Thats ENTIRELY the problem. At level 1 the Erebus through his or her early kills gets enough gold and levels to always have a leg up on their opponents. At the very least it forces your opponents to retreat and allows you to hold key flags which again gives you the advantage. If anything needs to be perfectly balanced it is level 1 vs level 1.
Then run from him at level 1, or gank him. People haven't realized yet that you can't win ever fight, and Erebus levels rather slowly with only creeps around. Two things all players need to learn: Lock flags FFS, and RUN when you can not win the fight. A good team will have complete map control and very few deaths. I won a 3v3 last night and my entire team was around 5 levels lower than the opposing team, but we had map control and jumped to catapult+giants with good timing and I made sure to constanlty shield my team with QoT.