[ VIM ] Вертикальное разделение окна в VIM. Как открыть разные файлы ?

:help noea *'equalalways'* *'ea'* *'noequalalways'* *'noea'* 'equalalways' 'ea' boolean (default on) global {not in Vi} When on, all the windows are automatically made the same size after splitting or closing a window. This also happens the moment the option is switched on. When off, splitting a window will reduce the size of the current window and leave the other windows the same. When closing a window the extra lines are given to the window next to it (depending on 'splitbelow' and 'splitright'). When mixing vertically and horizontally split windows, a minimal size is computed and some windows may be larger if there is room. The 'eadirection' option tells in which direction the size is affected. Changing the height of a window can be avoided by setting 'winfixheight'

На подвыбор пофиг, всё равно каждый файл синтаксиса имеет уникальное имя. Посмотри в папке syntax с вимовскими shared данными.