It's a ridiculous idea. Koukash, like a lot of very rich men, is clearly used to getting his own way. But this would please no-one: ESL would be (fatally?) weakened as the best English talent flocked to the NRL side, where would the team's support base be in Australia, the travelling cost (in money and time), and so on.
And supposing this putative NRL side wasn't a big success, but ended up in the lower half of the table, attracting dwindling crowds? You know, like Salford...
And,in fact, in the vanishingly unlikely event of this proposal going ahead, what would be the long-term prognosis? Eventually the team would start to recruit Aussies and Kiwis, and, just as the NZ Warriors aren't all Kiwis, this team would in the few years be of mixed nationality and hence indistinguishable from other NRL sides.