Description of the Command skill could be clearer

The description of the Command skill says:

You may only research one of the command skills in the categories
Offensive Tactics, Defensive Tactics, Discipline and Seasoning per
level of the barracks.

My initial reading of this was that I had to interleave barracks level-ups with researches in these categories. It took some confusion to prompt me to experiment enough to discover that what it actually means is that the number of skills - *ignoring* the sub-category researches for Offensive Tactics, Defensive Tactics, Discipline and Seasoning themselves - can never exceed the barracks level, but one can indeed not research any of these skills for a while and then research several of them, to catch up with barracks level, between two barracks level-ups.

I confess I can't find a nice or elegant form of words with which to express the rule I discover, by experiment, to be in force; but it may save other users some confusion if you can think of one, as the present wording confused me, at least.
The two points of confusion are that, first, the sub-category researches that unlock the skills are not deemed skills and, second, that the phrasing "You may only research one ... per level" suggests that, between one level-up and the next, one can only research one skill - which implies the number of these skills one has can't catch up with barracks level, if it ever drops behind.
One can, in fact, research as many as it takes to catch up with barracks level.
Perhaps:

You can't research more of the skills dependent on Offensive
Tactics, Defensive Tactics, Discipline and Seasoning than your
barracks has levels; if you're blocked from researching one
of these skills, you need to raise the level of your barracks.

would do.