Cape Town - Former South African cricketer Daryll Cullinan says different captains for different formats could lead to confusion among the Proteas ranks.Hashim Amla was earlier this week named as South Africa's new Test captain, replacing the retired Graeme Smith. He was picked ahead of AB de Villiers, who was named vice-captain.The roles are reversed in the ODI format though, where De Villiers is captain, and Amla his deputy. (In addition, Faf du Plessis is the T20 captain).Cullinan, speaking via a video clip on the ESPNcricinfo website, said Amla's appointment was a good one but he questioned South Africa's policy of having the duo's roles reversed across the Test and 50-over formats."What teams want to do is they want to identify with one captain. I think it's divisive when you've got two."Secondly, the more you captain, the better you become, so both would have needed that opportunity. "It's taken me by surprise, because it defeats that, in terms of what I'm trying to say."And how would they develop a relationship? Both would want to lead and I think, as we saw with the Graeme Smith era; the most successful (era), he was the leader and I think it's defeated the objective."Cullinan said the decision not to make De Villiers Test captain must be confusing and disappointing for the player."I can only believe, trying to make sense of it all, that they've based the decision around the 'keeping issue that they have at the moment. They clearly want AB to 'keep in Test cricket, believing (Quinton) De Kock's not good enough at this stage. "That's a fair point, but how do you make a Test captaincy decision around a 'keeping conundrum? To me that doesn't make sense."Cullinan believes obvious solution would have been to put faith in De Kock as the long-term wicketkeeper, and then give both (ODI and Test) captaincy roles to either De Villiers or Amla.Amla became South Africa's fifth Test captain since re-admission. Kepler Wessels (1992), Hansie Cronje (1994), Shaun Pollock (2000) and Smith (2003) were the others, although Mark Boucher, Jacques Kallis and Ashwell Prince have also done the job in a stand-in capacity.Amla's first assignment will be to lead the Proteas to Sri Lanka next month for a two-match series.CLICK HERE to listen to Daryll Cullinan's full interview on the ESPNcricinfo website.