You are right that tribal is hard to do in cube/limited (especially if you have more than one tribe in a colour). An exception is when the support is accidentally, like beasts. Onslaught has more to offer so I would suggest just ignoring tribal and only add support when you think the tribe is there. (My effort overdid the morph part, so it did not work out.)I keep wanting to bring my playgroup back to Onslaught, but most of us starting in a tribal environment doesn't translate well to cube or even to jumpstart. Our next set, of course, was Mirrodin, which is a disaster in terms of power balance. That said, my current main project (that's likely to get a thread soonish) is an artifact design. Nostalgia is hard to beat.
I know that Mirrodin had issues in constructed, but that also holds for urza block. Those issues can be solved in cube. Finally, a set cube is not only nostalgia but also not too many abilities and often some sort of balancedness (creatures from the same era and so on).
You are right that the power difference/mistakes are due to poor control, but it does not seem like that this has changed much. For my urza block cube the cycle is much less lopsided as one would expect:This is kinda true. There's definitely a bit of a power difference, but it's not nearly like it is today. I think some of that can be credited to WotC's poor card evaluation at the time. That's how the Academy land cycle ended up so lopsided. Mythics of today are primarily printed to sell packs, as well. They have to be pushed well above the rest, although a reject mythic draft would be a lot of fun lol.
Yavimaya>Gaea>manlands=Shivan>>>Phyrexian>>Serra>Tolarian. All decks play creatures so the cradle has more strength than the other 2 tap for x. Without really cheap artifacts/enchantments (who you want to play early) the others lose a lot and the drawback of tapping for zero is huge (cradle has this too, but much less often). For constructed the tap for x lands rule. Especially the Tolarian and Gaea’s. In the old days the rares also were to sell the set. Pfiew, can you imagine that the following was a chase rare?