Yeah, that sounds like an awesome workable solution. I'm not yet a @splinterlands tribe member. Once they get their referral program re-energised and secured, I'd be keen to join.
Just remember that there are many ways to reward members. Perhaps you could earn different skins like on Borderlands, or maybe get a number - being the number of referrals you have - attached to your handle? If payouts are hindering the growth of the site, then consider these other reputation rewards.