vs Landorus-T: True, however, after rocks, Ferrothorn has a chance to 2HKO Landorus-T. And that's with a +Def nature. Most Landorus-T run Adamant anyways. Adamant Landorus-T has 10% chance of getting 2HKO'd. After rocks, it's a firm 2HKO. Landorus can't touch Ferrothorn with its standard Rock/EQ/U-Turn/Stone Edge set anyways, so it can't switch in.
vs Gyarados: I'm pretty sure no Gyarados runs max HP and Def. Most are just offensive oriented. The two sets I've seen: RestTalk and Bulky Support are rare. Anyways, with rocks support, there's a chance to 2HKO Dos. Anyways, the two sets can't do much to Ferro either. Most Gyara that try to switch in usually goes for Taunt, at least I think so.
vs Scizor: Nothing to say there. It's a hard counter, but I'm pretty sure the Iron Barb damage might hurt.
vs Dragonite: Using your statistics, Ferrothorn can 2HKO after SR. If Dragonite doesn't carry Fire Punch then... The set is parashuffling right? Ain't got anything on Ferro.
vs Cress: Like what Sparkbeat said, ain't got anything on Ferro. Ferro still wins.
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The bottomline is that, you aren't us CB Ferro correctly. It isn't supposed to be Terrakion, come in and proceed to beat everything. CB Ferro's main selling point is its large bulk, accompanied by its large array of resistances and unpredictableness. Also, Ferrothorn needs some team support to make use fully.