Most of the Deputy Lanterns had their own special powers/skills to fall back on as well as the ring, and Scarecrow had the least to offer. I guess if he had time to truly master the ring, he would be a powerhouse, but as is, aside from the ability to make constructs, shoot energy beams, fly, etc, he's not much higher in terms of power than a seasoned Sinestro Corps member, imo, if at all.
Originally posted by Doctor-Alvis
It sounded like it was supposed to be a big deal to stop him from getting the ring the first time. I expected to hear him doing some high grade fear mongering.
I think his psychological expertise in the area of fear would give him an edge over most raw recruits immediately, but he didn't really do anything wowzers with the ring to suggest that he was a powerhouse. If anything, the thing made him unstable (well, more so than usual) and a liability for the other Deputy Lanterns.