I was recently asked to create a positioning chart for the alto trombone. My inclination was to recommend creating one himself since the physical act of doing it will benefit the learning process. But I realize that doing things the hard way is an acquired taste and I’m glad to do the heavy lifting.
The top part of the chart below is the first position (fundamental) overtone series juxtaposed with the same for the tenor trombone. The second part is a positioning chart from the pedal Eb to the high Eb. Keep in mind that the alto is a perfect fourth above the tenor. So are the harmonic anomalies like the 7th overtone being flat and therefore must be pulled up.
Overtone and positioning chart: (click to download)