but then you can't yank and paste between buffers since you will be using seperate vims.
you can try dwm.vim (https://github.com/spolu/dwm.vim) if you have spare keybindings.
if you are still not convinced and want to use screen, i recommend tmux since you can split both horizontal and vertical.
not really sure why.. (i have my screen tabbing with F11 and F12).