ATCT GND CTLR HAD 2 COMPANY MD80 FLTS MIXED UP WHEN ISSUING RWY XING CLRNC.

Narrative

DURING TAXI TO RWY 1L ON A TXWY JUST COMING UP ON A6; WE HEARD 'ACR X; CROSS RWY 25R TO FOLLOW COMPANY (ON OTHER SIDE).' CLRNC TO CROSS WAS READ BACK WITH CALL SIGN. AS WE MADE THE TURN TO CROSS RWY 25R; WE COULD SEE ACR Y BEHIND US ON TXWY B. AFTER RE-XING RWY 25R; WE HELD SHORT OF TXWY B; CLR OF RWY 25R; AWAITING ACR Y AT THIS POINT. GND QUESTIONED ACR Y ABOUT HIS POS ON TXWY B AND THEN RECLRED ACR Y TO CROSS RWY 25R AND FOLLOW COMPANY ON OTHER SIDE. LOOKING OUT THE TWR WINDOW -- GND THEN REALIZED THAT WE HAD CROSSED RWY 25R AT A6. AFTER QUESTIONING US AS TO OUR POS; HE INSTRUCTED US TO RECROSS RWY 25R AND TAXI TO THE RWY. GND CTL WAS VERY BUSY WITH 10+ ACFT TAXIING TO RWYS 1R/1L -- WHICH IS A NON-TYPICAL TKOF RWY AT LAS. WE BOTH HEARD OUR CALL SIGN; WHEN WE READ BACK THE CLRNC TO CROSS -- AND THEN SAW OUR COMPANY BEHIND US ON TXWY B. IT SEEMED TO MAKE SENSE FOR GND CTL TO DO THIS IF HE WAS LINING UP ACFT SPACING OVER DIFFERENT DEP FIXES. WE BELIEVE THE GND CTLR CONFUSED ACR Y AND ACR X CALL SIGNS AND DID NOT CATCH THIS ERROR ON OUR READBACK. THIS ALSO WOULD EXPLAIN WHY ACR Y HAD NOT CROSSED RWY 25R TO FOLLOW US. RWY 25R WAS NOT IN USE DUE TO WINDS. NO OTHER PROBS WERE NOTED.