[CORed]

Spotter/Big Player tactics have been around at least since Ken Uston's days (1970's). If your big player is the only person in the casino betting at that level, he will be noticed pretty quickly. Actually, the biggest advantage to team play is pooled bankroll and the ability to get more hands in in a short time. This improves the chance that variance won't break you before your (very small) longterm edge kicks in. The cover (if any) that using spotters and big players provides is, at best, a side benefit.

The first question you should answer before you try anything is whether the rules and penetration are such that the game is even worth playing. If two decks or more are cut off or the rules are particularly bad (H17, double down restrictions, no Double after splt, etc.), the game is probably not worth it. You may still have a theoretical +EV with a big enough spread, or back count, but your edge will be so small relative to variace as to make the real-world profit not worth the time or risk.