Group of soldiers has bad time in revolution (5)
I believe the answer is:
troop
'group of soldiers' is the definition.
(I've seen this before)
'bad time in revolution' is the wordplay.
'bad' becomes 'poor' ('poor' can be similar in meaning to 'bad').
'time' becomes 't'.
'in revolution' says the letters should be written in reverse.
'poor'+'t'='poort'
'poort' back-to-front is 'TROOP'.
'has' is the link.
(Other definitions for troop that I've seen before include "Force" , "Flock; Scout group" , "Military body" , "Porto (anag.)" , "Body of soldiers or scouts" .)