If subcool knows what hes doing the variation may very well be because he has parent plants homozygous for many different genes.
In my books that is a good thing.
If the TGA parent plants were inbred lines ("true breeding"/"homozygotes"), then the F1 offspring would all be uniform, or nearly so, and there would be no issues with phenotype variation.
But we know this isn't true.
TGA/Subcool's strains typically all start with hybrid parents, thus explaining why many/most of his line will show a wide variety of phenotypes. We also know this, because he says this.
"Good"/"Bad" is sort of subjective and it depends what you're after.
If you don't mind growing lots of plants and doing a bit of selection to find a few exceptional ones, then there is absolutely nothing wrong with unstabilized polyhybrid plants.
But if your ability to grow large numbers of plants is limited (by budget, space, legal constraints, or other factors) then this sort of polyhybrid lineage may not be for you.
Ultimately, the question isn't how many individual lines the seeds can be traced back to. . .that's sort of irrelevant. Even most of the stable inbred lines "could" be traced back to many different strains if you went back far enough.
The question is, in any given pack of seeds how many different phenotypes are you going to see, what variation you can expect between them, and how frequent/rare the "good" ones are.
That's what separates the true breeders from the "hacks"/"pollen chuckers".