I guess I might be able to say "different stokes for different folks." My Bavaria has sail drive propulsion; i.e., there is no shaft out the back. Consequently, it seems, there is no need for a deep "common bilge." The bottom is relatively flat, so bilge water is "spread out" rather than accumulated in one deep place. There are compartments which are isolated, at least to the height of the athwart-ship stringers. Short version--the bilges are easy to keep clean; pull up the holly sole and mop. I also flood the bilges periodically with fresh water wash downs of other, higher (inside) areas and pump out. When the boat was new there was a lot of wood debris (sawdust and shavings) coming down; but no more. So, there is no debris or trash in my bilge; not to say it could not get there if the boat rolled over, etc.
My point--a boat that is "holed" will see water flood into a clean bilge on my boat; thus, high capacity pumps are needed to meet that inflow while we hunt down and plug the leak. If the boat rolls over and gets water inside while dumping trash all over the place; then yeah--the impeller pumps will likely clog out. BUT--unless there's a doghouse missing and you're likely to take another roll and you are not yet sinking--you can apply the slower, manual dewatering methods [diaphragm pump(s) of your U-tube], or buckets. [But remember, "the best laid plans often go awry!" & "It's possible to do everything right, and still lose." It's the ocean, after all!]