"You want to perform at your absolute best in every event you do. By doing four that could compromise those outcomes.
"There are other athletes who deserve an opportunity to have a go at all events as well. It is pretty exciting, but we've got a few years to go, and a whole year to figure out what we're going to do at the next world champs.'"
Part of the issue is the Olympic schedule in Tokyo. It's not as if the spreading of events allows plenty of recuperation time in between. Some disciplines have racing as little as 40 minutes apart.
Walker has some concerns.
"To do all four is probably a bit too much at an Olympic Games, so we need to be strategic in how we choose these events for different people and how those athletes decide to focus on different events," he said.
"It's not just Lisa. There's another squad of athletes coming through. Caitlin is our second female world champion. There's Aimee and Kayla, all fantastic athletes. How we spread our talents across all events is going to be very difficult and a careful decision for us all."
Walker's own view is medalling in three events, let alone having a crack at four, will be an outstanding achievement.
A holistic view is important. The bottom line is success for New Zealand, rather than its stellar paddler.
"Some of the events, by the nature of the programme make it hard to do together. That's probably the biggest challenge," Walker said.
Carrington contested 10 races on the Racice course which was a remarkable performance. Her previous most at a regatta was six.
She's now up to 11 world championship medals, seven of them gold. New Zealand have never won four medals at a worlds, the previous best being three at 1987, 2013 and 2014.
The K1 200m is a special favourite for three-time Olympic medallist Carrington, the event in which she sprang to prominence at the 2011 worlds. She produced her second fastest time in the event on Sunday night.
"It was really special to be able to come back from Rio [Olympics last year] and to be able to perform. That was really cool.
"A lot of trust and planning went into it (her programme). Gordy, when he asked me if I wanted to do four events, obviously believed I could do it. But it's about making sure you spread your energy right through the weekend.
"Training with the girls in the K2 and K4 did change my training schedule a bit but it was a fun thing to do and it's nice coming out of an Olympic year and be able to do something different."
Now it's time for a break, for the paddles to be put away for a while. Then it's about dissecting how best to maintain a remarkable success story, both for next year and through to Tokyo.
