Hmmm I wait more than 10 secs but with the same result :\
Is your mount script still ended with the & character?
(sleep 5;
mount -t cifs -o username="Normandy Server",password=***,rw //192.168.1.10/Ngo/roms /storage/roms/;
)&
[following scripts]
This will cause the mount to wait x amount of sleep, but the following scripts will still start directly afterwards, without waiting for the sleep command.
If you remove the & it might wait long enough for the mount to be present when emulationstation boots.
(a separate sleep insert would be even better as the removal of the & will cause the boot to hang for quite a while, if your network share is down)