Hi. Sorry for my little english. I´m spanish and i have a dude. When Unit enter into Portina Brook and stop , can gain terrain if other unit retreat hexagon? Calvary may make a chalvary charge?
The Portina Brook is not a normal fordable river. Have special rule.
If I understand you correctly then a unit that enters the Portina brook and battles can not advance after combat because the brook stops movement. Cavalry can charge into the hex but would not be allowed to make a breakthrough attack. That's because again, the brook stops movement.