Baze Malbus 3* Chirrut

I currently have a Baze of 3 stars that has thought of farmear to Chirrut in the store of ships my question is it would be a good idea to go up to Chirrut and leave a 3 * baze? Is this combo useful in Arena in late Game?
Could you buy shards of baze in the store worth uploading to 4 *?
Thx.