It’s true what you said, Clark has an answer to everything, the thing is though, he does not have an answer to everything at the same time.
His air-to-air grab and j.CD are great anti-air tools, but if he commits to them and you stay on the ground, he can be blown up with tripguards and other forms of anti-airs
his ground game is great, but his normals aren’t the most dominant in the game. His other tool on the ground are throws, and there’s one thing that is really really great about this.
His command throw has a whiff animation, so if he commits to it and you jump, he’ll eat punishment. Even if he tries to normal throw you, his close C isn’t very good as an anti-air, so if he attempts a throw and you jump out, chances are his close C is going to whiff completely, so either way, he has to commit to ground throws.
Whenever I play against Clark’s I just play ‘the floor is lava’. Why bother with the floor at all, if you’re going to get grabbed anyway. But arguably, this isn’t the best of strategies due to his airgrab, but characters with high priority jump attacks might be able to get away with it.
Another option, which is very viable against clark, is learning to alternate guard. If you don’t know what that is, read my article on dreamcancel: http://dreamcancel.com/2011/09/25/the-king-of-details-2-throws-by-phoenix/
Alternate guarding is effective against Clark, as his low options aren’t as scary as his grabs, although, now he can cr.BA xx grab, it has gotten a lot scarier than in older KOFs. But with it, you can blow up any tickthrow.
On offense, make sure your jump-ins are tight. Your jump-in > normal should be an airtight blockstring, if it isn’t, your opponent might reversal grab you in between. Therefore, heavy normals are preferred as they cause more blockstun.If you catch the opponent trying to mash in between jump-ins anyway you can also use that as knowledge to purposely do a bad jump-in, and rehop into combo.
If the Clark player tries to use his B grab as an ‘anti-air’ in a similar way that people used to do this with invincible grabs in older KOFs, you need to stay on point. It is not particularly legit. Since you can ‘autoguard confirm’ your jump-in. and rehop on reactions, but you need to be mindful of it.
Maybe needless to say: never, ever empty-hop > low/throw on a Clark if he isn’t knocked down. And even if he is, this is what Clark wants you to do, he has instant throws.
If you feel the need to mix him up on the floor use normals that are outside of his throw range. In KOF grapplers cannot grab limbs, so a well-spaced sweep will make throws whiff.
Depending on your character, you might be able to outpoke him on the floor in general. I see you use Iori, for example, Iori’s st.D is magnificent. Good range, good priority. st.C is similar, but less ideal. Even st.B is pretty good to keep him at bay. just, NEVER commit to qcb+C. It’s safe against most characters (-1), but it’s unsafe on grapplers with an instant grab.
Don’t try to command grab Clark with Iori. Clark will win every time. Iori’s grab has 7 frames startup, and has no invincibility of any kind. That grab, in general, only really works if your opponent is mindfucked, which, if he OCV’s you 20 times, is not the case.
Claw Iori is also a character with the worst tickthrow potential due to high throw invulnerability, so no, don’t do it, he has plenty of other damaging options.
I hope that helps.