WING TIP STRUCK AN ADJACENT ACFT WHILE TAXIING FROM PARKING SPOT.

Narrative

TAXI FROM PARKING APPEARED NORMAL. WE HAD 2 MARSHALLERS DUE TO THE CONGESTED RAMP AND CLOSE PARKING SPOTS. ONE MARSHALLER WAS LOCATED UNDER THE R WINGTIP (NOT VISIBLE FROM COCKPIT) AND THE OTHER WAS OFF THE NOSE AT 12 O'CLOCK. THE FO CLRED THE R SIDE OF THE ACFT; AND I WAS MARSHALLED FORWARD; FOLLOWED BY A HARD L TURN. THE GUIDANCE MARSHALLER CONTINUED THE L TURN SIGNAL AND THEN GAVE US A 'THUMBS UP!' WHILE STILL ON COMPANY RAMP; RAMP CTLR CALLED US AND HAD US RETURN TO PARKING DUE TO A POSSIBLE WING TIP SCRAPE FROM THE ACFT PARKED ON OUR R SIDE. THE R LOGO LIGHT COVER WAS CRACKED BY THE STATIC WICK FROM THE OTHER ACFT. WE LATER LEARNED FROM A MAINT SUPVR WHO SAW THE INCIDENT THAT THE WING MARSHALLER ATTEMPTED TO SIGNAL THE NOSE MARSHALLER TO STOP US. HOWEVER; THE NOSE MARSHALLER WAS 'HEADS UP AND LOCKED!' AND NEVER GAVE US A STOP SIGNAL AND APPARENTLY NEVER LOOKED AT THE WING MARSHALLER! WE NEED TO TRAIN OUR MARSHALLERS TO LOOK AT THE WHOLE ACFT; AND ALL MARSHALLERS SHOULD BE IN VIEW OF THE COCKPIT!