Complex sentence: He is something of an anomaly among the giants of Torah study as he was supposed to have been in his early youth a bandit and a gladiator, although Tosfos says that he was a Torah scholar before his life of crime.
Split into simpler sentences: He is something of an anomaly among the giants of Torah study as he was supposed to have been in his early youth a bandit and a gladiator. The early commentators speculate that he was a Torah scholar before his life of crime.