Here's a shot of a crappie school, in one schooling form. Granted they can be more distributed at times, esp when active, but, we wouldn't mistake this for bass.

And while we're at it, here are gas bubbles being released from bottom silt, and a carp (at the edge of the cone) that released some of them.

Try using a Road Runner lure.  This is made for crappie but bass and perch will hammer this bait.

I guarantee I can put y'all on 8-12 Crappie suspended at 20-25' over a 40' creek channel and y'all will think they are bass; I can do the same thing with White Bass or Stripped Bass.

You are showing screen shots of what you already know exist

Yes, we can be fooled. And/or we do have to check things out to be sure. No argument there. The suspended bass in the first shot I wondered if they were carp, and didn't get an answer until I threw 'em a lure. Never considered them to be perch though. And I never did cast to that bubble raising carp either lol.

But you must agree that some fish can have characteristic sonar signatures, and contexts.

A friend and I were just sharing pics of crappie schools we shot. Mine was taken 1200 miles, 6 months later, and 40* different in water temp. Interesting, yes?

Mine:

His:

But you must agree that some fish can have characteristic sonar signatures, and contexts

No I must not 

You ever see a small school of 3 lb crappie at 25-30'?

You ever see a small school of 3 lb Strippers at 25-30'?

You can tell me which is which by characteristic sonar signatures and contexts?

Without knowing what you are metering in the above screen shots, there isn't any way to tell what you are looking at. School of crappie could be brush with a few crappie or any other fish that may be in that particular lake or river.

The only thing we can characterize is the shape of isolated fish echos; how fast the target moved through the signal zone can help when you know what type of fish are in the area. Example; stripers and trout tend to travel fairly fast through the water column, as compared to bass, but not always. The direction the target is traveling compared to the boats direction also affects the speed the target passes through the signal area, affecting the shape of the signal return.

All we really know is the sonar returned a signal display and it's up to each individual angler to interpret what they are looking at.

WRB

If the bass are suspended, you can catch them with a wacky rigged Senko, suspended under a slip float. Check the Senko articles above. There, I've outlined my technique, on just how to achieve success with it. It's easy to adjust the drop of the worm to their exact holding depth this way.

If they are on the bottom, then try drop shotting a 3" - 4" finesse worm vertically - right over them. Shorten the dropper so that your offering is only about 6" above the bottom. Do not over work the worm! This cannot be over-emphasized. A lot of long pauses between a few easy twitches, will get their attention.

If there is a stiff breeze and you are having trouble staying over them, I'd recommend anchoring; move the boat about 15 yards into the wind, ahead of the school. Drop the anchor and feed line until the rear of the boat is over them. The boat will swing slowly back & forth over the school and give you ample drop shot access to all fish there. Turn off your sonar as soon as you are properly positioned! There exists a lot of disagreement on the necessity of doing this; I do it just to put the odds in my favor.

At the same time you can put out your Senko float rig for added presentation and coverage. In this case of bottom holding bass though, adjust your Senko to hover about 2' off the bottom. The breeze will bounce and agitate the Senko, almost guaranteeing you a bite!

One of these two presentations will get you into your fish. Good Luck!

Pretty solid advice..but there are times when no matter what you do,,.it aint gonna happen! :-/