Well, I'm not terribly familiar with UU but 3 Evioliters seems a bit excessive... Again, I don't know UU that well so I can't really say much, but I do know Xatu and Amoonguss are both fantastic and both usable in UU. They can get away with playing in OU, and Xatu is even viable in Ubers for Magic Bounce. I use both frequently. If I had to recommend replacing stuff, I'd say use them over Dusclops and Gligar, but again, my UU knowledge is very limited xD
"Whether Castform the Weather Pokemon can weather the weather is dependent on whether the weather that it's weathering is the proper weather for it to weather. Whether the opponent can weather the weather is also subject to whether the weather that it's weathering is the right weather to weather. Whether Castform can weather the opponent is once again dictated by the weather and whether that weather is the favorable weather for weathering. But most importantly, you should know whether there will be weather to weather rather than what weather they will be weathering and whether they can weather that weather."
- Smogon's Castform analysis