Sorry, but that's an awful idea. Van Gaal is not a big fan of board-room interventions in his football plans. Woodward doing what you suggested will just lead to a million trust issues between CEO/ upper management and the manager, which is something that hastened his departure from both Barcelona and Bayern Munich. Some might point to Shaw and Ander from last summer as non-Van Gaal signings, but those deals were pretty much tied up before he was officially appointed.
If you have a proven manager who's been there and done it all, you must hand over the keys of football operation control to him, and trust his expertise in the field instead of trying to micromanage at every opportunity, which by the way seems highly disrespectful and something that was ridiculed in the past with the likes of Chelsea and Madrid. The latter part just smells like baseless paranoia, Louis' other signings hardly indicate that he's planning only for the short term.
The likes of Memphis, probably Darmian, Rojo, Blind are all at a good age and will likely be at United post-Van Gaal. Dunno where the idea of him prioritising short term gain and leaving the squad in a bad shape is coming from when he's also given opportunities to the likes of McNair and Wilson, while trimming out the big wage/ non-performing/ older members of the squad. If Van Gaal doesn't want Schneiderlin (no indications that he doesn't by the way) then I'd be in United's interests to back the manager they appointed in the first place.