Okay, let's remove Aizen from the equation. He stomps anyone he's matched up against, so that instantly decided this when you typed it. Add Ichigo in because he can go longer than 11 seconds now. We're assuming all Vizards have Shikai. We're assuming, Shinji and two other Vizards have Bankai, it's a nice number. Ichigo is added to this.
8 Vizard vs 10 Espada. Four Bankai, Four Shikai, Eight Hollows masks vs Ten Ressureccion.
The stats:
~Vizard~
Full Power Ichigo > Full Power Grimmjow
For the sake of raw numbers, we're going to assume at this point Ichigo = Nnoi, as he was already severely injured when he fought Nnoi before.
Full Power Shinji > Full Power Grimmjow
Shinji dominated one-armed Grimmjow with his mask alone. By this we'd guess Shinji roughly equals/surpasses Grimmjow with both arms. By that, Shinji Shikai/Bankai should be able to surpass Grimmjow Released.
Shinji's smart, he could easily use Ichigo's raw power by directing him. Bankai/Vizard Shinji and Ichigo working as a team should be able to overcome Ulqi, but that would remove them from the equation as well.
Those are the only two Vizard we can easily analyse, so let's go on to Espada.
~Espada~
Pre-Vizard Bankai Ichigo > Unreleased Yammy. Badly.
Through that, we can assume any Shikai Vizard could take out Released Yammy. Removing them both from the equation.
Same logic says Arranneio's gone.
Szyael is hard to peg down. Only a ranged fighter would be efficient against him, and that's guaranteeing he hasn't done prep. If the Vizards have a Ranged fighter who is only Shikai, that one and Szyael remove each other as well. If Szyael's done research and prep, there's gonna be hell to pay, it'll take an efficient team to bring him down. For the sake of numbers, we're assuming Szyael has no prep.
Zomari acting intelligently is dangerous to ANY fighter. The only way to beat a smart Zomari would be if you could focus enough Reiatsu to blow off his Amor or spam the wall Kidou like Byakuya. Hacchi and Zomari remove each other.
Grimmjow is taken down by a Bankai Vizard.
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Let's do the maths here.
We had four Shikai Vizard, one of which we assumed to be Hacchi. They took out Espada's 10, 9, 8 and 7.
We had four Bankai Vizard, one of which beat Grimmjow. Ichigo, Shinji and the remaining
Bankai Vizard team-crush Nnoi, but that removes the Bankai Vizard. Ichigo and Shinji escape mostly unharmed and bring down Ulqui, but that takes them out too.
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Therefore, our current eight Vizard have taken out Espada's 4-10. The top three VL Espada stomp. Aizen doesn't even need to lift a finger.
Major powerups are going to be needed to deal with high grade VL Espada.
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This scenario is based on the fact that the Espada and Vizard don't work as a team. The odds on the Vizard teamwork being superior to Espada teamwork are high, but the results of a team battle are hard to gauge.