There is no perfect strategy, because incomplete knowledge is rampant in pro sports.
The key to long-term success is learning from mistakes, and always making new mistakes.
The other key is the right owner giving rational mandates.
I think the Eagles were drunk off the SB, but even with the mistakes, making the playoffs 4 of 5 seasons is quite an accomplishment,
Howie is best when rebuilding, without a HC with pull dictating "win now" moves.
And Siri and Gannon are hands on coaches, so they have a better feel for the players they can coach up.
The reason they're so successful drafting OL is Howie defers to Stoutland's judgement. Stoutland is a hands on coach, focused as much on teaching fundamentals as blocking schemes.