Minor II V I exercise - wrong chord scales?

[joegold]

Am I right in thinking the suggested chord scales are not right for minor keys? In the case below, Dorian seems like it is wrong, the b6 should come from a Locrian scale to fit into Harmonic Minor, which is where the other 2 chords belong. Might be just me being naive, can anyone clarify? screenshot attached to explain what I mean. thanks!

The 2 most common chord scales for Im6 chords are Dorian and Jazz Minor.
The disadvantage of Dorian is that its b7 will clash with the maj 6th down in the chord voicing.
I.e. b7 is an avoid note on min6 chords.
The advantage of Jazz Minor is that the maj7 is an available extension.
Your ears can learn to play off of this chord either way.
Neither is 'right' or 'wrong'.

The most common version of Im throughout most of jazz's history has been Im6, especially in the bebop and pre-bop eras.
Im7 became more prevalent during the modal jazz era.

The scale most closely associated with a Im triad, especially in the Classical Period of classical music, is/was Natural Minor, aka Aeolian.

On Im(maj7), in jazz, the typical choices are Jazz Minor or Harmonic Minor.
Jazz minor has an advantage that the maj 6th scale degree works nicely as an extension.
Harm min has the disadvantage that the b6 is an avoid note.
But your ear might go either way, depending on the context.
It's usually not cool to overemphasize the b6 whereas it is very cool to lay into the maj 6th.

In jazz, and in classical too I suppose, on a Im triad, the typical choices are: nat min, dorian, mel min and/or harm min.
But even phrygian might work sometimes too.

So, no, the exercise isn't wrong.
The writer is just coming at it from a different perspective than you.