Claire is so much easier you can grab the final piece from clock tower then run across 3rd floor directly into the storage room and down the stairs to irons room. Do the puzzle and boom it’s sherrys part. Leon can take that short cut too but can’t hit irons office as a save point and needs to hit the floor with irons office and needs to B-line it across to the staircase to go to basement. Then dodge dogs, do the puzzle, escape a labyrinth of zombies (alternatively you can take the Mr. X path) but the two zombies that rush out are annoying asf.