Yes, David Tennant played Barty Crouch, Jr. in the films. (And yes, some of his icons are from DW but were still chosen carefully.) (He's not alone: Many of Snape's and Sirius's icons are not in-character.)

Where possible, we use the actual actors. There are exceptions (Narcissa, Zach, Justin) and there are obviously some original characters / characters who were not really shown in the films.