Alright, it states 'near Pevensy' so maybe the intent is that it is simply the closest marked town on the map (although in the map, it is 'Devensey' for some reason). The implication is that this is the place where Aelle of South Saxons has his naval base. However, in Saxons!, we find out that Anderida is a Cymric town that gets taken over by Aelle in 491, and all its inhabitants are put to the sword. This is also mentioned in the GPC, where the name of the town is 'Pevensey'.

I suspect that the thing is really that 'near Pevensey', since in Saxons!, Aelle's center is Mealling (South Malling), which is like 20 miles west from Pevensey. It is on the River Ouse in Sussex, which is the river in the Pendragon color map west of Pevensey.

Still, this could be clarified in my opinion. :)

Alright, it states 'near Pevensy' so maybe the intent is that it is simply the closest marked town on the map (although in the map, it is 'Devensey' for some reason). The implication is that this is the place where Aelle of South Saxons has his naval base. However, in Saxons!, we find out that Anderida is a Cymric town that gets taken over by Aelle in 491, and all its inhabitants are put to the sword. This is also mentioned in the GPC, where the name of the town is 'Pevensey'.
I suspect that the thing is really that 'near Pevensey', since in Saxons!, Aelle's center is Mealling (South Malling), which is like 20 miles west from Pevensey. It is on the River Ouse in Sussex, which is the river in the Pendragon color map west of Pevensey.
Still, this could be clarified in my opinion. :)

It is an error
It is Anderida in pre-Saxon times
Replace Pevensey with Pefen's River
And make the first landing somewhere appropriate

And be sure to list thse in the Errata section