i don't think zonal marking was a success. i think the worse we got the more corners we gave away tbh.
and its not just signings, though dossenna cost 7m could have been forced to buy someone better for that cash. its the football ,not good enough. roatation and cautious football meant we always off the pace, until that one year when xabi just went ballistic in his passing. fergie signed poor players sure but he always went for wins ,rafa was too worried about tactics.
We weren't off untill the last year, when H&G just stopped the transfer funds, we were becoming a real threat, if it wasn't for H&G I think we still would hold the most league title record.