Actually, Simon, the fact that TD has had to bring in 11 linemen is pretty damning. The best OL's are not necessarily the ones with Pro-bowlers from LT to RT, but ones that have been together. If any part of the team needs time to gel to work well together it's an OL and one of the key common (granted not all the time, but more often than not) attributes is that the line sees no more than one personnel change from year to year, most frequently none.