The drafted players acquired by Hendry over this period combined to accumulate 11.6 WAR in the majors. The top five WAR totals were produced by Sean Marshall (6.6), Casey McGehee (3.7), Sam Fuld (2.1), Tony Campana (1.4), and Darwin Barney (1.3).
Epstein’s draft haul over his tenure with the Red Sox amassed a total of 85.9 WAR, led by Dustin Pedroia (24.5), Jonathan Papelbon (17.1), Jacoby Ellsbury (13.6), Clay Buchholz (8.9), and Justin Masterson (6.3).
It must be taken into account that Epstein likely spent more than twice as much as Hendry on the draft (having trouble finding this data), but Hendry likely had similar resources at his disposal if he chose to allocate them towards the draft. Even so, Theo clearly got much more bang for his buck. I think this was obvious to us, but seeing the actual numbers makes the contrast even starker. See the WAR totals for every major leaguer from their drafts in this spreadsheet (I tried to delete all non-signed players that were later drafted and signed by other teams.) I'd also be interested in seeing a comparison of international free agent signings and MLB free agent signings if any one feels up to the task.
(Data from Baseball-reference.com)