I phrased that poorly. I meant that the design, WITHOUT turbofans, did almost nothing.
Yes, but by that logic, they can just catch up, they'll be one turn behind for two turns....if they choose to counter. The best bet is to throw this out NOW. As you've been saying (I think? I don't think I've gotten confused as to who's who yet) for a few turns, "What if they do a new jet now?". Well, we'd have a hard counter to that by rolling out the jet now.
By the way, if the Turbohaast is Hard, this will be Hard. Because it is basically Trivial (25% increase in autocannon size is all that adds definite difficulty), since I know nothing about how hard Sensei will rate "Extreme aerodynamic improvements like we've done on every other aircraft so far". As far as we know, this would be a Normal design, as would the Turbohaast (Two tonnes of bombs) without the turbofan. However, since difficulty isn't strictly additive, adding the turbofans ought to leave both aircraft at a Hard difficulty.
The Turbohaast is a fun idea, for sure. But fun is not what we need. The Haast does it's job well, and by unleashing a better fighter NOW, we let the Haast do it's job. Basically, we've seen in the past that having aerial dominance is incredibly beneficial, much more so, in my opinion, than rolling out a new attacker.
Ultimately, both should help. But I believe that the jet fighter will help more. It leads to fewer helicopter drop-offs (Not, you know, that their useless Twinblade is anything but, uh, useless), fewer hostile bombing runs, MORE friendly bombing runs, less hostile CAS, etc.