I like the FA defence signings for the most part but it's easy to see that they bought time with this contract. I do like Woo but his first complete solid season was probably last year, the previous year he improved as the year went on but wasn't that great at the beginning IIRC.
With the injury recovery and just trying to build off his first good pro season it makes sense to sign him for two years. Desharnais and Forbort are only 2 and 1 year signings, if Woo develops they can move off those guys.