Bloom sure looks like a carbon copy of Epstein--Yalie who loved baseball (but only Theo played in HS but not at Yale) and went into MLB right out of college.
However, three big differences: 1) Bloom grew up in one system, the Rays, which placed a premium on developing players because buying them was out of the question--the Rays have consistently had team payrolls near the bottom of MLB; 2) Bloom literally wrote the book for the Rays system of developing players, especially pitchers, which has proven to be very successful; 3) Bloom's entire MLB experience was with the Rays, whereas Epstein worked for the Orioles and Padres before coming to Boston, which means Epstein was/is probably more adaptable.
I think Chaim Bloom was a great hire, but I am less sure that he will be a good fit because the Sox are consistently profitable even when John Henry approves team salaries among the highest in MLB. Neither he nor his GMs nor the Red Sox Nation are known for their patience.
Also, if Chaim Bloom intends to overhaul the Sox entire system, how receptive will all those scouts, coaches, minor league managers. etc be? The movie Moneyball exaggerated (for dramatic effect) the negative reactions of the scouts, A's announcers, and especially manager Art Howe to all the trades and moves Billy Bean made, but there was a kernel of truth in there. Heck, had I been an A's fan, I would have said Billy Bean was nuts.
My guess is that Chaim Bloom, who wrote an article published in Baseball Prospectus in 1997 (when he was 14) and has therefore been a real student of the game for 23 years and an MLB professional for 15 years, already knows all of the above and will steer a course that blends the three approaches: 1) spending some real money where it makes sense, but 2) bringing team salaries down comfortably below the MLB salary cap, and 3) at the same time building a badly needed system for developing players, especially pitchers. Item 2 has already begun, and 3 has probably been initiated in some form, but so far I haven't seen examples of 1 (spending real money on players where it makes sense).