Your team is great, but you will probably start having difficulties if your competitors start developing toons like Shoretrooper to prevent Biggs' one hit KO and fast Boba Fetts and fast TFPs to debuff your entire team afterwards.
If you continue farming Baze (I've enjoyed him at 5* g11 for a couple of weeks) and gear up your 4* Chirrut (I played mine at 3*, g9.5 for 2 days now along side Baze) you will have another great duo there to team up with your Wiggs. Add either your current St Han or maybe a fast and geared Boba Fett and you should be able to keep your rank easily.
Baze works on his own as well, but Chirrut more or less needs Baze to protect him.