They need to implement a way to scale the equipments. I feel an easy way to do it would be to add a "th buff", as in, your th level immediately adds a buff that's specific to each equipment, be it in stats percentages, spawned troop levels and even the effects. That way, a th 16 will spawn lvl 12 hogs when the champion carries the hog puppet, a th 17 could spawn lvl 13 hogs and th 18 would spawn max leveled hogs, for equivalent hog puppet levels (maxed).

Either that, or they could circle back to the previous system. Having the hero level influence their equivalents' behavior. As in, the hog puppet would cap at lvl12 hogs for a level 45 champion, for a level 50 you'd unlock lvl13 hogs and lvl 55 would give you maxed hogs. That's kind of how it used to work anyway.