Part of the problem is your employee count is wrong. The latest figure I found for WAG's employee count is 93,000. It's probably higher than that now, but nowhere near 154,000. 105,000 seems to be the correct number for CVS.
Store Base (as of October 31, 2003) Total stores: 4,247 in 44 states and Puerto Rico Locations with drive-thru pharmacies: 3,306 Locations with one-hour photofinishing: 4,167 Locations open 24 hours: 1,144 Walgreens Pharmacy/RxPress stores: 38