I think you're right. In fairness to the devs, it's strange to go back to undergeared troops, and sub-optimal teams, but it is a bit refreshing when the tuning supports that, and the new variety is interesting, much more than probably have a right to expect from an older mobile title given the current emphasis on maximizing monetizing FTP games and gamers.
I opened a lot of chests, to include gem chests from my gem stockpile that I was saving to blow on trying for a new Mythic of interest, and was able to ascend the Shentang troops. I was dismayed that I was unable to pull from a chest the Epic troop that is in the store, that is specifically designed for Boss battles, makes me wonder if it's not available outside of the store? However, with my buffed Shentang troops I was able to make it through the gauntlet and put 170 damage on the boss.
I may bite the bullet and get the one from the store, I have "free" gems available to invest, and the Boss' one-shot kill ability is no joke. If one can Ascend that troop with the anti-Boss Palm Strike ability, and then Trait for the "Godslayer" Trait, along with the Barrier to avoid the Boss' one-shot kill ability, it would be great to have. However, if we can't pull it out of chests, it would be costly to get enough copies out of the store to Ascend it to Legendary and then Mythic, which is what the text about the ability scaling (both Palm Strike to 5x, and Godslayer to 5x) looks to require.