It's not that regular/classic/wild type of PK's is bad...... it's just a criteria we humans brand them by. VT and classic PK are things of the past. People prefer HM, HMPK, HMDT etc.
If you breed a HM to a classic PK, you won't get any HM in the fry.
Dragon scales is a cross breed between regular scaled splendens and wild betta which makes the scales look thick. What ever scales or tail type, they are splendens and can be cross bred. But to cross anything you'd have to have a plan, unless you're willing to either house or cull hundreds. Because other people wouldn't want them so you can't sell them.... the so called "mutts"