I have to congratulate you on this pretty original yet nice looking team.
Now to the point. I see that you dont have a classical defensive wall which is bad because choice scarf salamence can take down your pokemon one by one just by switching in and out. Thats why i would suggest you changing your Gastrodon to a Slowbro because with him you will be able to tank hits extremely well.
Now that you have a great Defensive wall you dont need a Defensive Reuniclus anymore. Thats why you should run a more offensive one. I suggest you a Recover + 3 Attack or the same set as you posted but the Def evs go to Sp.atk. You chose which suits you better. Now you will be able to make wholes in your opponents team.
I kind of think that Scolipede is not the right option for this team. I know it does set Toxic spikes. Since you said that the whole team is based around him i wont suggest anything. But try the suggestions i told you and tell me whether scolipede is efficient. I will come back to this thread later...
P.S The Slowbro set should look like this
Slowbro @ Leftovers
EVs: 252 HP / 252 Def / 6 SAtk
- Thunder Wave
- Slack Off
- Ice Beam
I put ice beam so that you have a direct coverage to Dragons
It is nice to be important but it is more important to be nice