sasha19md
Shouldn't be, If you check the Pictures or the assembly Video you'll see that two tires should fit quite well on one rim. It's hard for me to know what problem you have without seeing anything.
This is a semi truck toy with a tank trailer. It is almost the same as https://www.cgtrader.com/3d-print-models/games-toys/toys/semi-truck-toy-fully-3d-printable-assembly-experience but with the semi truck havind two rear axles. So the assembly process is more or less the same as for that one.
For the tank trailer print as many middle modules as you want to get the tank length that you want.
The tolerance for pieces that need to fit tightly is 0.1mm, for pieces that need to allow movement (like screws and axles) 0.3mm or more.
Printing list: Nb. STL file name rezolution support colour (my make)
Observations: