If you want to make something better, get with him and do it.
As for adding the button on the site, I wouldn't personally recommend it, as it is not related directly to Argo itself. A text-based link, like the one at the bottom, would be best for a partner site like that, (just as the same would apply to Paruni's site with an Argo link).
If we had a different site design more accommodating to those kinds of partner links, then I'd say go for it. Unfortunately, most SMF themes aren't really built in such a way where that would make sense visually. It also probably doesn't help that our communities are so large in size, so their partners, services, and advertised affiliates are way too big to list in image format, hence the text-based link setup already used.
If you're looking for a way to attract players with image links, however, I'd recommend posting the buttons on other sites where you can legitimately advertise gaming communities. That would much more likely attract new people, especially considering that most of Argo's dedicated members are already aware of Paruni's existence. (That being said, I would also strongly advise that the Paruni text-based link in the partner site section not be removed either, as that is how you would attract the few "stragglers" that don't know about Paruni in Argo).