Setting up Sturdy Shedinja

I'm going to offer an alternate setup which may be more viable, and gives Smeargle more of a chance to survive. Like you mention, Sturdy Shedinja is a two turn setup, and you don't want Smeargle to be vulnerable for both turns, otherwise it'll go down.

In this strategy, we lead with Carbink & Smeargle. Carbink gets Sturdy and Skill Swap, which is perfect for what we need. That way, Smeargle doesn't have to worry about doing the actual copying.

The crux of this set is Kings Shield on Smeargle, which stops attacks but not status moves, allowing Smeargle to protect itself whilst receiving Sturdy. It has the same priority as Protect, so will stop Fake out, and it will lower the attack of anyone that hits it with a Physical move, potentially making them switch out.

The order of moves is therefore

• Carbink uses Skill Swap on Smeargle, Smeargle uses Kings Shield
• Carbink switches out to Shedinja, Smeargle uses Entrainment on the switch

The three issues I see with this type of strategy:

1. If Smeargle gets double-targeted on the second turn, it may not get a chance to use Entrainment
2. Shedinja being hit by a Super Effective move on the switch before Smeargle can give it Sturdy
3. Carbink getting faked out first turn

The first & second are also present in the Smeargle/Sawk set. The third we are mitigating the risk to Smeargle in place of complete protection from priority, and relying on the inherent threat of Smeargle (Dark Void or otherwise) to take the heat off of Carbink.

Anyway I believe this strategy maximizes Smeargle's survivability in this situation.

Notes:

• Assuming somehow that Smeargle survives the third move, you could run Transform and change into a second Sturdy Shedinja, albeit without the Safety Goggles
• If Smeargle goes down, you can switch into something else for Safeguard
• Switch Carbink back in for Explosion, which can deal a great amount of damage whilst Sturdy Shedinja takes none.
• Potentially run Choice Scarf on Carbink to move before some threats, swap away Sturdy and go down, allowing Shedinja a free switch in
• Have something (Smeargle if it survives, or a Prankster Pokemon like Klefki) use Thunderwave on Shedinja on the third turn. That way it won't take Burn/Poison damage either