Yeah, I supposed that. Besides, it's very unlikely that what happened there would repeat. I just wanted to have a few monsters on there because Altarix is a present time rider, so he still faces them. Probably they will hide when the thing gets ugly and probably comeback once the treat is gone. Besides, once they leave Altarix's town, he might stay to hunt and destroy them (too much hatred, for the same reasons Aranz dislike the mod warriors)
P.S.: You might like having Aranz showing them they are not made for this war. Very likely, the Empress will retreat... crying. Period.