Jim didn't plan for it, as can be seen from the beginning of the stream where Jim is being very belligerent.
Ralph started off high-energy - he'd probably been knocking back booze and/or pills in the pre-fight when he kept mysteriously switching the camera off for a minute or two.
If Jim responded in kind, it'd just end up in an unintelligible screaming match that would go nowhere. Instead, he mocked Ralph's entire approach - calling him a ragepig, imitating his puffed-up mannerisms, noting his "hollerin'". The belligerence was Jim subtly moving the battle into more favorable territory by making Ralph look like a fool if he kept up his initial Alex Jones assault. He's signalling that Ralph is only hurting himself and will have to tone it down to a more civilized exchange.
One clear advantage to the calmer approach: Jim
probably did goad Ralph deliberately with the Gator/Flamenco appearances and approving references to "Fake Jim". And he
probably did change his name for anonymity reasons, only now realizing he could have done it better. But he has plausible explanations for both, and in a calmer setting he can just lie. Since Ralph has no proof to the contrary, he looks paranoid by pushing it once those explanations have been given. In a shouting match, with no time for longer explanations, both attacks would land.
What Jim probably didn't count on was the sudden drop-off from whatever he'd been chugging in the minutes before joining the stream. His energy levels dropped like a sack of shit, and by the end he sounded like he was struggling not to puke. He'd been counting on a first-round holler-out but instead punched himself out against Jim's solid defence of sarcastic mockery.
His quitting to Jarbo was funny, but I don't think it was that much of an own - he'd been beaten up by the Portuguese, then by his surrogate daddy. He's wanting to throw up, and here comes Matt Jarbo of all people, fully sober and starting off with the hard questions. I think he just thought nah, fuck it, I've taken enough of a hammering already, I'm not giving
him a chance to start kicking my ribs in.