Complex sentence: Even though Roy Tarpley was signed and Aris was dominating in the start, things fell apart and irresponsible management in conjunction with lack of discipline led to the 5th spot in the final standings of the Greek League.
Split into simpler sentences: Even though Roy Tarpley was signed by the team, and Aris was dominating at the start of the season, things eventually fell apart. Irresponsible team management, in conjunction with a lack of discipline, led to the team finishing in the 5th spot in the final standings of the Greek League.