If you don't have a holding mid behind them, I'd certainly go with Veloso to solidify your D.
I'd only go with Pastore + Hamsik if you have a destroyer behind them IMO.......but if you do, its an ideal combination, because Hamsik can just be an MC/attack with Pastore taking playmaker responsibilities. Hamsik one of the few extreme creative mids that doesn't have "dictates tempo" or other skill that requires him to be the playmaker.