In my personal opinion I think out of phase is going to be somewhere been a wash and negative, so I sorta disregarded it when thinking about the balance of the dudes in my extended thoughts below:
I do agree that, compared to high elves, the linemen are probably better. 7av means that roughly 14% (~17% vs mb and 0% vs claw) of blocks on them that would have previously not broken armor will do, however fend is a good secondary skill for them, and a free secondary is... Probably. Worth that extra armor. The catchers also seem better, +10k for another good secondary.
Throwers are worse, -10k for -1av and -1 primary skill makes the etherals significantly less good. Blitzers are worse as well. -10k for -1mov.
So about half the players are better, half the players are worse.... But I sorta agree with the end point of your analysis. The other teams do seem weak compared to the top vanilla factions (although they are so weird it's hard to tell for sure), and although high elves might not be the best elf team (probably the wood elves?) no elf can be discounted. So I think the Ethereal will be top tier but very fragile team. And potentially need to be nerffed, or other teams buffed. Maybe (it's hard to tell with how weird the teams are). Although in a long league they are simply going to loose a lot of dudes to injuries, and will really struggle paying for replacements as well as keeping up with other teams on levels, so in that environment I think they'll be a little bit weaker.
Although I do think you're overestimating them in how much they will want to punch. Assuming the other players coaches are good at the punching game, very expensive and very fragile isn't a mix I would want to have when wading in. The low armor is going to mean loosing a lot of guys very fast if they accept any punching game that they don't dominate in, and with the expense of their players they won't have a bench (or even an Apothecary at first) to keep in the game. I don't think the Ethereals want to punch in against any of the other teams shown so far. Maybe the gnomes.