Smooth exercise on horse in first gymkhana has them on an equal footing (5,7)
I believe the answer is:
level pegging
'them on an equal footing' is the definition.
I can't tell whether this defines the answer.
'smooth exercise on horse in first gymkhana' is the wordplay.
'smooth' becomes 'level' (I've seen this before).
'exercise' becomes 'pe' (Physical Education).
'on' is a charade indicator (letters next to each other).
'horse' becomes 'gg' (geegee or GG is a childish term for a horse).
'first' suggests taking the first letters.
The initial letter of 'gymkhana' is 'g'.
'level'+'pe'+'gg'+'in'+'g'='LEVEL PEGGING'
'has' is the link.
Can you help me to learn more?
(Other definitions for level pegging that I've seen before include "could it straighten out one's hang-ups?" , "unlikely when camping in the mountains?" , "Even scores" , "Uniform state" , "All square ... at cribbage? ..." .)