Let’s look at OP’s original complaints.
I’m so sorry for your TDS team but there is more than one dragon. This synergizes very well with Sheggra, and you could make a “3 dragons and Infernus” team where the hero’s weapon combined with this might actually be stronger than Sheggra’s ability.
DRACOS 1337 has this ability and is a Dragon/Mech. Looking over the Mech types, there are a lot that are boosted by armor. Could it be that this is some kind of acknowledgement that you might want to be Dragonguard for, say, GW reasons, but use a Mech team in another event? There are some possibilities here that might get interesting if more Dragon/Mech troops or Mechs that synergize with dragons appear.
OK, so there’s no Dragon/Raksha to talk about. But Ubastet’s pretty damn powerful and already self-boosts its Magic. So what if we make Hero / TDS / Glitterclaw / Ubastet"? We get 3 dragons worth of bonuses, and Ubastet’s gaining +2 Attack and +1 Magic every turn, not to mention Faerie Fire makes Ubastet’s ability “Destroy 2 troops.” Very nice.
The purpose of these abilities aren’t to make the hero into an uber-troop like Infernus that you can put on any team to make it more powerful. If “Dragonguard + 3 dragons” were insanely strong, it’d be as problematic as Divines. The purpose is to have a powerful and flexible troop that opens the door to teams that can’t happen without the hero. The things you listed mean that hybrid Dragon/Mech and Dragon/Raksha troops AND teams are more powerful today than they were yesterday. The concept of a Dragon/Mech would’ve been “meh” before this. Now we know there’s a class that will specifically benefit that type.
That means, in the future, lots of dual-type creatures are going to be more powerful than they look, and several hero classes are more likely to have a niche.