sorry but this is just wrong, well-baked zamac is simply not a good check. for one, tera normal facade does over half, but importantly facade has 32 PP, meaning that zama is VERY prone to being recover stalled (especially given that you have to recover really early to not just fall to spikes and +1 facade) even if it doesn't have to deal with strength sap blocking. fur coat steel + well-baked ghost seems fine until you realize that you are running a fur coat steel + well-baked ghost team, which folds to practically every non-slaking physical attacker in the meta (koraidon, groudon, hoopa-u, and even more niche ones like caly-ice and rayquaza), and slaking is always paired with koraidon or hoopa-u to take advantage of said structures.Look, I'm not trying to say that Zama-C is the perfect check here, but doesn't it do a good enough job? I'm not running Zama to beat arceus or other fast 120 speed special mons like palkia, so I think +Def is absolutely justifiable. You don't outspeed koraidon either way. Also if you fear sapblock, you can also run recover. Just because counters to sap exist doesn't make sap a bad move though.
+1 252+ Atk Guts Tera Normal Slaking Facade (140 BP) vs. 252 HP / 252+ Def Zamazenta-Crowned: 249-294 (64.1 - 75.7%) -- guaranteed 2HKO
Zama has quad rock resist and is immune to toxic so chipping it is harder than you'd think. You'd need to chip 30% which is also not a small amount. I'm sorry but I think your comparison with FC garganacl is absolutely laughable. Zama is faster than slaking, immune to toxic and rocks and has STAB Body Press to threaten slaking back. I don't know how you can consider both of them to be the same level. If the opponent havent scout the ability and click v-create, you can OHKO with +2 press.
+2 252+ Def Zamazenta-Crowned Body Press vs. 252 HP / 252 Def Tera Normal Slaking: 476-564 (94.4 - 111.9%) -- 68.8% chance to OHKO
Here are some calcs to prove this mon can be threatening unlike garg:
+3 252+ Def Zamazenta-Crowned Body Press vs. 252 HP / 252 Def Groudon: 237-279 (58.6 - 69%) -- guaranteed 2HKO after Leftovers recovery
252+ Atk Groudon Precipice Blades vs. +3 252 HP / 252+ Def Zamazenta-Crowned: 110-132 (28.3 - 34%) -- 0.6% chance to 3HKO
On a side note here is an imposterproof spicy flutter mane set which walls non wicked blow slaking and WBB Annihilape:
Flutter Mane @ Spooky Plate
Ability: Flash Fire
Tera Type: Ghost
EVs: 252 HP / 252 Def / 252 SpA / 252 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Substitute
- Nasty Plot
- Judgment
- Torch Song
Annihilape @ Leftovers
Ability: Well-Baked Body
Tera Type: Ghost
EVs: 252 HP / 252 Def / 252 SpD / 252 Spe
Calm Nature
IVs: 0 Atk
- Strength Sap
- Cotton Guard
- Body Press
- Substitute
Anyways I think WBB zama or an offensive ghost type possess enough qualities which make them deserve some experimentation to beat guts slaking. That is all.
Another edit: I suggest running an FC steel alongside a WBB/FF Ghost so you can wall all the common slaking options. Remember the Ghost can be a setup mon and not a stupid passive wall like garganacl. FC Zama/Kingambit + FF Flutter for example.
for the fc garganacl comparison, i would actually say that garg is simply the better slaking check, as it doesn't actually lose to slaking unlike zamac. it's still not good, because it loses to koraidon, can still get PP stalled out of recover, and sucks at direct damage, but it at least does the job you want it to. zamac having the benefit of body press isn't also that significant because people will usually still be carrying any of haze, imposter, or a ghost-type to basically nullify it completely (nobody good at the game is going to try and 1v1 a zama-c without knowing the ability prior, so getting a surprise +2 press just doesn't happen).
tl;dr wbb zamac is a fake check, fc zamac + wbb ghost is a bad structure (it checks slaking but no other physical attacker unless you want to use 3 phys walls and never actually win the game)