The spacing on them should be standard. I've owned 4 Eriba's since 2003 and not heard of anybody needing to move them for an awning specifically designed for the van.
The only thing you may need to consider is the central bracket design might require you to adapt or get a different end for the stubby pole that locates in it.
When buying your awning make sure you get one the correct height. Your van looks like a pre 2010 so you need the lower awning. Vans after this date had a higher rail.

Colin