I completely agree on your second point - 2 year ban with break even restrictions vs 2 year ban without, clearly the latter is favourable (although I wouldn't trust UEFA not to put some monitoring restrictions in the detail of our sanctions meaning we had to comply before being reinstated in year three).
But on your first point, we signed Yaya and Silva without CL that year - but it was on the promise that they join our ever improving side and make it happen, which they did after year one. The 2nd year for both, we were in the CL - have been ever since. Players can usually deal with a year out of the competition - but a 100% confirmed 2 years out? As KDB intimated, that's a different scenario entirely.
Aguero we signed with CL football. We've played in the CL every single season he's been with us, so he's never had to take even a single year out of it.
Tevez was a unique set of circumstances, as he and his agent wanted to make the Rags suffer for pissing them around - and we profited. Sad though it makes me to say it, Tevez was more like Pogba and Sanchez - he followed the money, which pointed to us at that stage in our development.
Few teams in premier who don’t qualify for champs league keep there star players Hazard for one.