"We're delighted with their excellent standard of wicketkeeping," he said. "But there's no doubt both were short of runs. Tom and Luke are aware of that more than anybody.
"However, it wasn't long ago Tom was a really good performer for us at the top of the order. Both are quality players who have gone through a tough period."
Latham has made 35 runs from his last seven ODI innings, but topped the New Zealand averages on the ODI tour of India with 244 runs at 61 as a specialist batsman. He completed his ODI best of 137 in the Boxing Day match against Bangladesh.
Faith in Ronchi's batting requires a more elephantine memory. He has not passed 50 in 32 ODI innings since clocking what remains the world record No.7 score of 170 not out against Sri Lanka in Dunedin on January 23, 2015.
The wicketkeeper decision will be deferred to May's tri-series with hosts Ireland and Bangladesh, when both players could feature in an Indian Premier League-depleted New Zealand side. Latham could captain the team in Kane Williamson's Sunrisers Hyderabad-enforced absence.
"That series will be critical to establish a pecking order for the balance of the side," Hesson said.
The coach felt the development of all-rounders Jimmy Neesham and Colin de Grandhomme was a series highlight, meaning they are likely to keep their places in the premier starting XI. The upshot is if Ronchi plays, he's likely to slot in at No.5, ousting Neil Broom. Broom was in his pomp at the start of the home limited overs summer with 22, 109 not out and 97 against Bangladesh and 73 and eight against Australia. That faded to four runs from three innings against South Africa.
"It's nice to have someone in the top five who keeps," Williamson said. "That gives us balance. With 'Ronk' we've tried him at the top, which was tough. He's batted with success at No.5 for Wellington, so that was the thinking."
Conversely, opener Dean Brownlie demonstrated quality strokeplay to get starts of 31, 34 and 24 in three of his five ODIs against the Proteas, but could not capitalise further.