Both can to some degree, but being diesel units without any speed overmatch(the opposite is true) whatsoever - it won't be their forte.With increased power for propulsion, 054B should have higher top speed. Does it means 054B has the speed and endurance to operate in a CBG where as 054A couldn't?
Though I am a tad bit disappointed if it doesn't have IEPS
Given how much Chinese fleet is imbalanced towards surface combatants (and still counting) - I doubt there will ever be a lack of 052D/055 units to fill the desired composition.
They can be put well out of the main formation as listening pickets, though. With Fujian will probably still be meh, but with Liaoning/Shandong can work out due to their launch maneuvers (i.e. speed of advance is lower than tactical speed).