Normally this is simply errata, but if in doubt, always go with the listing of the weapons on pages 98 to 101. Often in games the description part is just fluff, but in Chronopia 2e your right there are rules and modifiers listed in the description. Read on Two-Handed Weapons (p 94) and in the third paragraph it reads: "When a Model armed with certain Two-Handed weapon is in Close Combat with multiple attackers he may perform a Sweep Attack."
The key is interpreting the meaning of "certain", it uses the term: Certain and in the context of this sentence that would mean only some two handed weapons, and not others. Which ones, the ones listed with May Sweep.
"When you use certain two handed weapons you can make a Sweep attack.
Any two handed weapon with the listed "May Sweep"
I have my rule book handy so if you want any more help just post.