One thing that I seen Stampede Wolfwood often characterized as by folks is well... distant is probably the best word for it. Mopey. Averse. The sort of guy who you wouldn't catch asking for a hug on the worst day of his life.
But I don't think that's true. Or at least, not beyond being a front he puts up. And there's one scene that for me confirms it. Because when Vash gets shot in Julai, Wolfwood's first response isn't to attack back.
It's to run over, put an arm out for support, and check in on him. Only when Vash shows himself to be okay do we see Wolfwood tell these people to back the fuck off.
You could read motivation into this act of comfort. There's fuel here for shipping, or perhaps Wolfwood is that terrified of his boss's mark getting injured. But it does also pair nicely with another scene not a few minutes later.
"My body moves before I can think."
In the split second before someone gets hurt, Vash isn't considering whether or not he should help them. He just does. The desire to protect is something so deeply ingrained in his core that it has become pure instinct.
And I think it's the same with Wolfwood. The moment that he takes to put up that shield of unbothered-ness is a moment too late. Big brother Nico has already taken action.
And even when he's just messing around, for someone who is meant to be cold and uncaring, Wolfwood's suspiciously handsy. This scene between him and Meryl would not have the same affectionate 'bickering siblings' vibe if he didn't insist on throwing his arm around her.
He's trying to mask it here by being annoying, but there's affection here. Not just emotionally, but through physical touch. Proximity too - guy's not adverse to getting up in people's faces to nick (ha) stuff.
And even at his most hostile and snappy, well, there's no strict reason why he has to get so close to Vash and grab him by the shirt like this:
But is it really a surprise that Wolfwood's like this? After all, the flashback with Livio shows that he was absolutely an affectionate and caring kid, even if edgy-teenager logic would have it utterly mortifying to admit out loud. The Eye of Michael can try to beat it out of him all they want, but a desire for closeness isn't something you can just remove from someone. It may end up muted, sure, but deep down it will always still be there.
TL;DR Wolfwood is absolutely secretly the biggest cuddlebug on this godforsaken planet and you can't convince me otherwise.