Bill Holman had a Rollins phase too. My guess would be that Way Out West was a strong influence at the time. As for Giuffre, within less than 2 years after Ad Lib, he was of course off on a substantially different tangent. As far as Giuffre's Verve stuff — non-arranger-wise — I'd recommend The Easy Way, 7 Pieces, In Person, and Ad Lib, probably in that order. They're all worth hearing if you're a Giuffre fan. It really would have made a good Mosaic set, I think.