the Inspire was actually a rebagded TL as all Inpire/Sabers originated in the US at first.

The Gen 6 is acutally the same all over the world in platform.
The basic floor pan and suspesion are the same. The dimensions were just en-larged for the US market first. The US is the world's largest auto consumer, as such it made sense to have a US specific larger chassis and V6 as that is what the NA masses wanted. In-turn, enthusiast now get the Euro/JDM Accord for sport as a side item in the TSX. With the Accord US and UK/JDM looking so different it makes sense for Honda to try and cash in selling both cars globally under new names per respective region.