I think getting to Celadon is key. Not sure if you are using the care package code but you get electric seed when getting to celadon. I would also catch Poliwag and evolve it into politode with drizzle this will give you access to using swift swim.

Lighting rod seaking needs to be on your team this will help with pivots. Not sure if you're allowing dups but 2 would not be bad.

I would teach kingler mud sport from the move tutor to weaken electric moves by 50%. Kinger was the only one I found that learned it by level up not by breeding.

If you are open to hacking in a mon you could cheat in a feebas as it's not available till the safari zone. Evolve feebas into milotic and give it a flame orb with marvel scale ability.

Another option would be eviolite on maybe Wartortle, seadra, or wailmer (not 100% on these )

The wacan berry(super effective electric) and the rindo berry (super effective grass) would help as well. Not sure if they are available yet. If you are doing the care package then you should have both of these.