You haven't told us how long ago your last cruise was....however MOST cast members are on a 6 months on, 2 months off contract. Assignments are moved around to accomadate vacations, so there is no guarantee that the same cabin will have the same steward.
You can always request a particular server. In addition, after boarding, you can go to "Dining changes" and ask who your server is. If you don't like the answer, you can ask to be moved to someone else. You also may or may not have the same dining rotation as you had last time. Rotations are loosely assigned based on the ages of the children and the age distribution on the ship, but it isn't totally firm. Thus, one rotation is primarily toddlers/young kids. Another is primarily adults alone and older kids. However, where the line is drawn between young/middle/older kids varies from cruise to cruise based on the age distribution of passengers on board.
Actually, unless you request a particular server, the chances of getting the same (and especially the same team) are rather small. We have a favorite server whom we request on a regular basis. I think we've had him with 6 different assistants--never the same one twice. Most of the assistants have gone on to be promoted to servers an moved to the Wonder.
A January 15 cruise will have a lot more little kids than a spring break cruise.....