There is nothing logical about taking four accounts of the same event (the crucifixion of Jesus), each of which refers to
two people executed with him, and use subtle differences between them to create a super-account in which now
four people are executed with him.
Your approach ignores what Matthew and Luke
individually write in order to harmonize real or perceived discrepancies between the two accounts. It is clear reading each account that
two people were crucified with Jesus... each author groups particular points together for rhetorical reasons. Matthew places notice of the other executions immediately preceding reference to the various groups who ridicule Jesus, culminating with notice that the robbers taunted him in the same way (27:38-44). Luke, on the other hand, groups notice of the three executions together (23:32-34). There are similar rearrangements of material in the crucifixion accounts... Matthew places reference to the written charge against Jesus (This is Jesus, the King of the Jews) after noting the soldiers cast lots for his clothes and sat down to guard him (27:35-37) whereas Luke groups it thematically with the soldiers mockingly adjuring Jesus to save himself if he is 'the King of the Jews' (23:36-38). Luke includes reference to the offer of sour wine in this context whereas Matthew places it immediately after onlookers think Jesus is calling out for Elijah (27:47-48). Luke places the tearing of the temple curtain before Jesus dies (23:45-46) whereas Matthew places it afterward (27:50-51). Examples could be multiplied if we factored in John and cast the net wider in the Passion narrative or the gospels generally... the point is that these kinds of rearrangements abound and are not an indication that the events narrated happened more than once or that there must be double the characters involved. These are the kinds of differences expected when two or more authors narrate the same event...
They went to the crucified individual on one side (referred to as 'the first'), then to the one on the other side (referred to
not as 'the second' as if moving in a straight line but as 'the other'
singular), then to Jesus... was that really all that difficult to surmise from John's explicit claim there were
two others crucified with him (19:18)?
There is actually debate as to whether asphyxiation or hypovolemic shock is the cause of death in crucifixion.
To what pre-mortem "gaping sword wound in [Jesus'] side" are you talking about?
You're welcome to think that and at the end of the day who really cares, but if you're interested in what the gospel writers are actually trying to convey rather than creating a harmonized super-narrative, your belief in five crosses on Golgotha that fateful day is the erroneous one...
Kind regards,
Jonathan