Hull KR's halves Albert Kelly and Terry Campese have the unpredictability that causes teams problems, says Widnes playmaker Kevin Brown.
Kelly, 24, and Campese, 30, were signed by coach Chris Chester from Gold Coast Titans and Canberra Raiders for 2015.
Despite only arriving this winter, the pair have been involved in 21 of 45 Rovers' league tries this season.
"It's hard to coach against, you don't know what Albert's going to pull out," Brown told the BBC Super League Show.
"He's going great and he's great to watch. We did video about Hull KR and the halves, the combination with Campese, Terry can get you with a pass while Albert can run straight through you."
Chester has quickly managed to forge a team spirit despite 13 pre-season signings and subsequent arrival of Dane Tilse and Shaun Lunt.
Macksville-born Kelly, who had previously been sacked by Cronulla and Newcastle Knights but rebuilt his career and reputation on the Gold Coast, has been a major part of that with his personality.
"He's special, he's a freak and we're really glad he's playing with Hull KR," Chester said.
"He does a lot of defending and he can create something from nothing."
Manly Sea Eagles, who could potentially lose Daly Cherry Evans as well as Kieran Foran from their halves for 2016, are reportedly monitoring Kelly's progress.
However, he has two years after this season left on a three-year contract and is enjoying life in East Hull.
"He seems happy there on his cultural journey and he's playing good footy," ex-Great Britain coach Brian Noble said.
"His partnership with Campese, in terms of balance, Rovers seem to have it there."