I HAVE and GOSH ever since i change nattrei for shubarugo, my winning rate goes into SKY HIGH position. His bulk, beast stats, ENOUGH movepool, and baiting is really benefical to my team. So much taht i can say that hes my crimgan of round 2 suspect.
BTW i use SD, Horn, Head, Pursuit with full HP full attack LO and it really work well. Carry some nattrei handler and your ready(natts cant really beat shubar though)
Bottom line, if you havent try it yet, TRY it. Used right he wont let you down with THAT beastly stats.
i'd try it with SD, Horn, Rock smash & Rain dance (it give support to my kingdra & reduce his weakness to fire) with some ev i've setup a lot of sword dance on nattorei. But the idea to use a more offensive spread isn't bad :D