Gengar solo

I think you’ll need FS on Alakazam. He’s too fragile for the cool down of non stab moves to take extra damage from fast attacks in between firing a Shadow Ball.
If not power up your Lugia a bit and replace that Alakazam and have him at the end as an anchor.

In my experience having two Lv 30 Ttars makes gengar a lot easier to solo. They can usually take out half the health in about 80-85s. So you have 4 slots for the other half.

I personally find sludge bomb to be harder since Shadow Ball is easier to dodge. If you’re beating him by thirty seconds then you have enough fire power, but can you survive long enough to use it? I’d say finish powering up the Ttar it has way more utility than a dedicated raid tank. Finally, if you are still having trouble with sludge bomb consider swapping in a Dragonite or double ground rhydon/golem(which you likely already have and wouldn’t require much investment). The rhydon/golem will double resist the poison plus is super effective.

The Tyranitar is a much better option to power up since it has much better DPS and resists both charge moves. It's also a pokemon you should power up in any case.
With the second Tyra at L30 you should be able to handle all movesets.

My girl account is only level 32. She can solo all gengar moveset easily. Against sludge bomb Pokemon with a low CD fast move is best like pc on alakazam and sucker punch or Shadow claw on gengar if u are lucky to have one because sludge bomb hits so fast that it's very hard to dodge with moves like confusion. Shadow ball is easy with one or 2 ttar plus u can see it coming a mile away compared to sludge. She uses level 34 espeon c/fs, 34 gengar with sucker punch Shadow ball, 2 34 tyranitar b/c, level 30 gengar hex/shadow, level 30 espeon against focusblast and sludge bomb. Against shadow ball she uses 2 34 tyranitar, 34 gengar, 34 espeon, 2 30 tyranitar. With tyranitar u don't need to dodge at all. Maybe just one per ttar if u need to get the last couple crunches off. Dodge with espeon and gengar. She always has around 15-30 seconds left depending how many charge moves she gets off with her glass cannons. U should be able to solo all moveset as long as u dodge properly. If u faint and come back in and fail still, power up ttar not lugia. Crunch as a 3 bar move will help and u resist Shadow ball.