Actually, as the former owner of an '89 Toyota 4x4, I can say the Tacoma and the Hilux are NOT the same vehicle with a different name.
The Tacoma is designed specifically for US/Canadian markets only and is built in Toyota's plant near San Jose, CA. Its biggest difference from the Hilux found in other markets, and even the previous generation (89-94) US model Toyota trucks is the front suspension.
To compare 2WD trucks, the Tacomas use a coil spring front suspension. OTOH the Hilux, and the previous generation US trucks use a torsion-bar setup.
There's an even bigger difference in the 4x4 models. The Hilux uses to this day old-fashioned solid axles front and rear. The US models went to IFS (independent front suspension) with torsion bar springs from '86 to '94. The Tacoma uses IFS with coil springs since its '95 introduction. While IFS gives a better ride, solid axles are perceived to be more robust. It's also easier to lift a solid axle truck than one with independent suspension.
Toyota, like many other car companies, are introducing market-specific models that have no relation to similar-sized models in other markets, even ones with the same name. For example, for the last several years the Corolla sold in Europe looks nothing like the Corolla sold in North America. It makes particular sense for light-duty trucks as Americans/Canadians tend to use them as leisure vehicles, while overseas they tend to be worked much harder.
