I would argue that though yes, they have undoubtedly deteriorated physically with some age and the rigors of NHL seasons in their rearview mirror, they have become much smarter and calmer players. That can actually benefit really smart, skilled guys. Wheeler is coming off back to back career seasons, and, despite a very slow start, and more responsibility centering his own line, Wheeler is still on pace for 25 goals and 71 points this year . I don't think Wheeler has really been impacted by age, I think it's made him a more complete player. As for Little, it's really hard to tell as he's really taken a beating over the last few years - poor guy, he's such a beauty. However, if he comes back healthy this break for his body might actually have him fresh with lots of stamina for the playoff push.
That is my long- winded way of saying this edition of Wheeler Little might be even better than olden days when they played with Ladd. Having a better 3rd with them (Laine or Ehlers) and moving Little to the wing (where he's scored 30 in a season) could end up being a pretty special 2nd line. The bonus there is having 2 good centers on that line for defensive awareness and faceoffs.