Tbh the only person who can answer that question is you.
Why are you asking us what YOU want to do with YOUR pokemon ?
But, to try and help you decide however...firstly, what do you feel you need ? do you want to have a strong daily gym defender count ? do you need coins ?
Or do you feel like you need a strong attacker ? do you actually battle gyms often ? and if so...why ? is it to place a defender or just to take gyms down?
I personally have a 3100CP DT/O Dragonite, hes my 2nd ever Dragonite and i was very happy to get lucky and role this moveset.
Hes is currently sat in a gym, because in my opinion the strong gym placement is Dragonites best feature and the main thing that makes him so attractive/desired by most players.
I mean...sure hes strong as a Pokemon too...in terms of using him to attack, but if doing damage in a gym battle is required, there's plenty of other adequate options as long as you pick the right typing/moves for the job. Most strong Pokemon have a counter pokemon that don't really work as defenders but are good at offense.
overall...i would say, go and battle with him abit, have some fun, actually use the moveset and see what its like, but if you get the chance, pop him in a gym and let it do what it does best, its not permanent and its not like you will lose access to him for ever.
