I always thought that it is best to only use the first of Given Names/Prenoms line and the Surname for many of the airlines booking systems. When adding more GivenNames I believe there is the risk that they all get merged into a long continuous name and that in itself could cause other issues

just to clarify further, I believe the machine readable line would be P<CSDSURNAME<<FIRSTNAME<SECONDNAME etc, so as far as the SURNAME (that in your example looks to also be the same as Name 1-2-3) and FIRSTNAME match, you should be fine. Is this the way that it is broken down on the field next to the picture? (Surname made up of three names)?

edit 2: out of curiosity I went to google Egypt Passport format (assuming the person in question flying from Cairo hold such a passport) and I can see where the confusion comes from as there is only one line for the full name (not broken down by Given Name and Surname). However in all the examples shown, the surname was the last name listed and the first in the machine readying line before the << separation to the given names that are each separated by a single <