Realistically, no. In a comic scenario where they'd undoubtedly write the mind-controlled or evil JLA as <<<< their normal selves, maybe. Hal does in fact have the most potential power on that list (sorry to the Superman fans) but in practice he's usually beneath Supes and could lose 1-v-1 to MM or Flash if he's not smart.
Except that scan is the beginning of Hal describing his plan which is then actually performed by the "good side of Hal imprinted on the ring" Marty/Thom.
Yeah that makes sense. As mind controlled indidivuals they would be less powerful than their normal selves. I do think it would be an interesting story if it were to happen.
To me, Hal always seems a little depowered when he's part of the JLA. He shines more when he's standing alone or leading a group of lanterns. I remember back when yellow was still a weakness, and he couldn't use his ring to affect Mongol, so he used his ring to amp himself up and beat Mongol in a fist fight. I remember thinking, wow what could he do if his ring actually did affect him?? And considering that Mongol has stood toe to toe with Superman, I don't find it out of the realm of possibility that Hal could find a way to win.
Of course it depends on the writer and story situation, lol.
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Actually flash can't vibrate through gl force-fields. Power ring has trapped flash in his force field and wally couldn't escape from it. GL shields are very successfull against intangibility, john trapped j'onn in one.