Teams following smooth Commonwealth forces (9)
I believe the answer is:
ironsides
'commonwealth forces' is the definition.
(cavalry founded by Oliver Cromwell)
'teams following smooth' is the wordplay.
'teams' becomes 'sides' (I've seen this before).
'following' says to put letters next to each other.
'smooth' becomes 'iron' (I've seen this before).
'sides' put after 'iron' is 'IRONSIDES'.
(Other definitions for ironsides that I've seen before include "Cromwell's army" , "Oliver Cromwell" , "Several Edmunds" , "one showing great fortitude" , "Those having great stamina" .)