Beyond the competitive dynamics, the critical issue for Toyota is what happens to the overall midsize pickup market in the next few years. And that's a subject of debate.
"The pool of people interested in a midsize truck is close to as big as it's going to get," said Stephanie Brinley, a senior analyst at IHS Markit. "Tacoma, because it's the big one, has the most vulnerability to losing share."
Brinley sees the segment growing a little in coming years to perhaps 475,000 from just more than 452,000 last year, and certainly not breaking a half million. "One of the things keeping it down will be just that the U.S. market isn't growing as fast as it was, and actually we're seeing some contraction over the next few years," she said.
That math makes it very complicated for the Tacoma to continue losing market share without losing volume once all of the new players are on the field, she said.
Others see some reasons for optimism, beyond the lure of fresh product and despite last year's slowdown.
AutoPacific's Sullivan points to the growth in sheer dimensions of full-size pickups as a sign that buyers will continue to downsize to more maneuverable trucks. The GM twins, which were an instant hit, "prove the point that people are willing to pay a premium for a pickup that fits in their garage," he said.
KBB's Brauer sees younger millennials favoring the smaller trucks as an urban lifestyle vehicle and older millennials buying them for home improvement as they move to the suburbs.
Lentz insists he's not worried. The Tacoma has proved to be a survivor when the segment is growing and when it's shrinking, as in the early part of the decade when competitors fled in the wake of the U.S. recession.
Still, he's mindful of the pressure so many new players can put on demand — a problem that all the competitors must confront, he said.
"The question becomes: If you add Ford's sales plan and our sales plan and GM's sales plan and Nissan's sales plan, are we all assuming that we're going to sell more than where the market is?"