Well, the data presented in the map (actual or ancient) is just a subjective decission of the cartographer or the writer of the article or the magazine's staff.
In this map, the data is actual. BUT, just because the map just want to illustrate the march in Eyipt and middle east, so main features are actual data. This makes it comprehensive to the reader so they can compare actual features with the map content. Its not a map representing the 1800's geography. Just as Suez Channel may be represented or not... in this case no. Just subjective. The appearance of the map is just style to make a "mind" game about the article and art (photographs etc...)
This is a usual cse I encounter with historical maps... and it's just a matter of communication. For example: A map of the Netherlands , may be drawn as today's coast or as it was earlier... it just depends about the author or the information contained in th map. If its about those islands that today are joined to the continent but in ancient times there were channels and ships need to be representes moving in them...
Or The zone of Guadalivir river in Spain which in Greek times was a sea, The river Ebro Delta didnt exist till 1600's, the Nle delta was smaller... etc--
Well, as I mentioned, it is just a communication matter between the author, cartographer and reader... totally subjective...
I would like to share a map published in Historia National Geographic this month about Napoleon in Egipt.
I have tried to make it look somewhat like the maps that Napoleón's engineers & cartogrpahers made int that campaign. As always , maintaining today's cartography accuracy.
I like your stylistic work. Thank you for sharing it.
Given the historical nature of the data being presented, I am disconcerted to see a depiction of the modern Dead Sea. That piece of the map is not important to your narrative, but to see a portrayal of its modern form leaves me wondering if important elements of the map might also be presentist, casting a shadow over my trust of the map.
— daan Strebe