It sounds like you may be trying to do too much in your weekly review. You're right, of course, that you can't do a weekly review in which you spend 10+ minutes on each of your 400 projects. But, in my experience, if I've got everything caught up properly, a review of most of my projects takes no more than 1 minute per project (and most of my projects are complex lawsuits). I don't try to do strategizing during my weekly review -- I have to set aside other time for that, during which I note the "next action" or "waiting for" item in my project notes. During the weekly review (which is not yet happening on a weekly basis!), I scan those notes to make sure everything's on track; I may realize that I need to remind someone to do something or take some other action myself. But I don't try to DO those things during the review (unless they're 2-minute tasks). The problem that I have (and this may be your problem, too) is that I am NOT up to date on all of my projects. That's because I started GTD in middle age rather than at the beginning of my career. I've accepted that it is just going to take some time to dig myself out from under the pile of papers and un-done tasks that I've been creating for the last decade.
If, after getting reasonably caught up, you still can't get through a weekly review, it may be that you are trying to do more than humanly possible and you need to either delegate more or decline more.