On other hand, that's really all you can do with this raid to make it remotely challenging.
Feraligatr has a somewhat varied offensive movepool but on other hand his utility pool is pretty lacking. You can't even get "creative" with scripted Breaking Swipe / Bulldoze / Snarl / Icy Wind cause of Sheer Force.
The only remotely creative thing I could say if they don't want to have DDance in its regular movepool is having Scale Shot in it and have the AI use it to gain speed advantage I suppose, as it isn't affected by Sheer Force.
Without DDance in the moveset, honestly I think Contrary Lurantis with Worry Seed probably is the best "independant" pokemon you can run.
You "just" have to live the first hit (+Def nature has bit more odds to live multiple turns)
0+ Atk Sheer Force Tera Dark Feraligatr Ice Punch vs. 252 HP / 252 Def Lurantis: 136-162 (39.5 - 47%) -- guaranteed 3HKO
0+ Atk Sheer Force Tera Dark Feraligatr Ice Punch vs. 252 HP / 252+ Def Lurantis: 124-148 (36 - 43%) -- guaranteed 3HKO
Worry seed, tank another
0+ Atk Tera Dark Feraligatr Ice Punch vs. 252 HP / 252 Def Lurantis: 104-124 (30.2 - 36%) -- 43.5% chance to 3HKO
0+ Atk Tera Dark Feraligatr Ice Punch vs. 252 HP / 252+ Def Lurantis: 96-114 (27.9 - 33.1%) -- guaranteed 4HKO
Then you can just recover off
0+ Atk Lurantis Leech Life vs. 0 HP / 0 Def Tera Dark Feraligatr: 132-156 (42.4 - 50.1%) -- 0.4% chance to 2HKO
and then buff yourself with Superpower after the buff clear pulse.
Alternatively, you run Jolly 252 speed, lets you outspeed Adamant Feraligatr and Worry Seed before it attacks, meaning you only tank the 2nd hit
0+ Atk Tera Dark Feraligatr Ice Punch vs. 252 HP / 4 Def Lurantis: 136-160 (39.5 - 46.5%) -- guaranteed 3HKO
I think tera BUG is the best option in such scenario, boosting your supereffective Leech Life while also making the croc use Liquidation to intentionally try and get the defense drop proc which turn into defense up.

Lurantis @ Shell Bell / Leftovers / idk maybe Big Root or something
Ability: Contrary
Tera Type: Bug / Fighting
EVs and Nature:
Impish / Adamant - 252 HP / 4 Atk / 252 Def
OR
Jolly - 252 HP / 4 Def / 252 Speed
- Leech Life
- Superpower
- Worry Seed
- freebie moveslot, maybe Tera Blast or X-Scissor or Ingrain