Small Pony Syndrome??

[Chilledoutfilly90]

I have a dun 11.3hh welsh x he has just turned 5 and hasn't been the easiest at times however under saddle he is good with me but can be excitable at times. He used to be terrible going out/ coming in from the field and would rear up and be strong etc so I started using a chifney which helped the problem, now its rare we use the chifney as he is usually good when I'm taking him to or from the field but as he's on full livery now due to my work the yard girls handle him they are all experienced and would never hurt him I trust them totally with my boys. But now he is becoming naughty again he kicks/ bites others when he's walking with them (not mares though) and goes to kick the girls when there doing his rugs when he's eating (he's never done this with me) he also has pushed one of the girls over several times when being led sometimes beacause he is scared other times he's just being a pig! I did think he had become naughty maybe cus he's going up the pecking order in the herd and showing others he will look after himself?
Has anyone got any ideas/ equipment/ experience in this to help my pony stay out of there bad books!!

 

[be positive]

He is on full livery the grooms can surely handle an 11.3 pony properly If not I suggest finding a yard where they are up to dealing with him, get him working to use some energy in a productive way and stop letting him rule the roost.
Putting rugs on while he is eating is not a good idea, if they are scared of him they should treat him as they should treat any horse in their care and tie him up to do rugs then feed after releasing him, not leaving the feed ready and letting him rush to start eating as soon as he comes in, it sounds a very unprofessional yard which is probably not giving him any boundaries and he is taking advantage.