Running EP, Vader, RG, TFP and Shore as my arena team and I can constantly rank top 10 in a late march shard. Planning on subbing out RG for b2 once my Shore hits gear 10, and once my b2 is improved and modded, in order to counter other shoretroopers and bazes.
The key to running a successful empire team is all about having an auto taunter (Shore is better here as he can actually synergize with EP) under an EP lead along with TFP. Without an auto taunter, your team will not be able to beat wiggs unless your TFP is faster than the enemy Biggs, but doing that is quite difficult. Without shore, you will also struggle against droids as they will kill your EP and maybe your TFP with their initial damage.
In summary: no Shore/baze = minimal success with an Empire team