The ICAO requirements for a Comercial are what the FAA now uses.
Explain to me the logic of requiring the comercial to be done in a
complex aircraft when most of GA training is done in fixed gear. All
any one needed was an endorsement for complex... But now the test must
be in a complex.

Then, explain why you need 3 landings on the 250NM straight, 300NM
total. By the time you are working on a comercial you should know how
to land, right? ICAO says you have to have the 3 landings and this must
be SOLO.

Wanna ask the FAA why? Have fun, because they will quote you ICAO.
So yes, the ICAO even specifies training.

Later.
Steve.T