I did suggest vehicles myself in this very topic,
it works significantly better both for story and set design than combining the toa themselves,
a system action theme needs action sets after all, can’t be just brick built rahi and scenery.
I believe someone tried to argue that because Lego Minecraft(a licensed theme of one of the most popular games on the market which is based on structure building) does well with a structure based set lineup, that g3(an action theme which is on its second resurrection and is an original IP) would be successful with a structure focus as well, despite Lego clearly shifting away from structure sets in action themes over the years for presumably financial reasons, ergo they don’t sell as well, for example: city is mostly vehicles, you get the occasional scenery piece and usually one structure a year.
All this is to make the point that g3 would be dead in the water with a structure focused set lineup, which is why I suggested repurposing the kaita title for vehicles.
I realise this post was a touch wordy, but I wanted to reiterate that point: that people need to look at g3 as a realistically successful action theme, and not a line of set pieces, regardless of how many gimmicks you say you would cram into the b.u.r.p.'s.