On the Manjaro Linux Keyboard Layout page, you will find that they build the
keyboardctl utility which makes it possible to change both the console and X11 keyboard layout at once, like so:
sudo keyboardctl -l us
For X only, you would use
setxkbmap us (session) or
kbctl -l us (permanent). In the console, you would do
loadkeys us (see /usr/share/kbd/keymaps/i386/) (session) or you would edit /etc/vconsole.conf to include
KEYMAP=us to implement the change permanently which should make things easier in the context you described.
Manjaro also uses the systemd system management daemon and is based on Arch so the Arch Linux documentation may provide different but complementary information.