If you want the wing backs to attack more, you've got three options in my opinion.
1. Move the wing backs up the pitch in the tactics screen, placement of players can considerably change the way your team plays.
2. Check to see what mentality your wing backs have. Are they defensive minded? Balanced? Offensive? If they are defensive they will sit back, offensive minded will always look to push forward, and balanced is balanced. If you need to play a defensive game to avoid defeat put in wingbacks who are more defensive minded. This can make a rather large difference in the way your team plays (this also applies to the problem you are having with your CBs)
3. As already mentioned, change the team style slider for player support to 20. However let me make a point. If you have your player support to 20 offensive, this only changes the entire team as a whole. Now let's imagine each individual has their own built in player support slider. If you have your team player support set at 15, a central midfielder with balanced mentality will have a player support of 15, if you changed your team to 20, the CMF will go to about 18-20. But for a sideback/wingback, if your team is set at 15 he may personally be set at 8-10 depending on his mentality, if you move the team support to 20, his personal team support may go to around 15.
This prevents every single player on your squad from charging the box, which allows you to maintain some formation shape and discipline. If you really want all your player to charge the box, use the All Out Attack tactic with full attack emphasis (little colored bar), even then some players will tend to stay back more than others.
Hope this helps.