Hi there!
This is a neat team you have here, utilizing a solid defensive core stacking hazards, which can then be abused by Rotom and Scizor who easily force switches. One thing I have noticed is that your team is pretty weak to stall. Your opponent can easily rack up hazards on you and as you have no Rapid Spinner, you cannot get rid of them. This will limit the switches Rotom and Scizor have, as they will be quickly worn down by said hazards. Your main option against stall is Rotom's Trick, which by itself is not reliable to beat it, although crippling part of a defensive core. To help with this, I recommend running 60 Speed EVs on your Jellicent, as well as trying out Taunt > Shadow Ball. This is especially helpful for your team, as you do seem quite weak to hazards, Taunt prevents your opponent from setting them up. Coupled with Jellicent's bulk and recovery, you can actually take on a lot of common defensive threats that are common members of stall teams, such as Blissey, Chansey, Skarmory, Reuniclus and others that have intentions of setting up hazards, phasing, boosting or statusing -- all of which look problematic for your team. The 60 Speed EVs help you outspeed things such as CB Scizor and Tyranitar, both of which can be statused as they switch in, or U-Turn out. I'd also highly recommend you try Will-O-Wisp over Toxic. I think that Pokemon such as CB Terrakion and Landorus can cause you some problems, especially when you have no rapid spinner. CB Terrakion 2HKOs everything on your team, while your only options are to revenge it with Scizor / Rotom. Using Will-O-Wisp means you can actually buffer Terrakion to an extent, burning it on the switch or catching it locked into Close Combat or X-Scissor. This also applies for a plethora of other physical threats, given the high reliance on Skarmory to deal with physical threats.
I'd also like to touch on your Amoonguss set, it does seem a little inefficient to me. Running that special attacking investment with only one Special move that deals decent damage seems a bit of a waste to me. I recommend that you try Hidden Power [Ice] over Clear Smog. Running Hidden Power [Ice] on Amoonguss allows Amoonguss to avoid being set up fodder for things such as Sub DD Dragonite, who does look annoying for your team when hazards are up and Skarmory is weakened. Hidden Power [Ice] also allows you to hit other Dragons for notable damage, such as Haxorus and Salamence. Losing Clear Smog is not really an issue, as most common stat boosters such as Keldeo, Dragonite, Haxorus, Terrakion and Thundurus are all crippled by Spore / Stun Spore, and can be dealt with by your other team members.
Cool team, hope I helped!
