Each classification has separate events on the men’s side, but they are combined because of a lack of participation, entries, etc. (whatever reason/combination of reasons) on the women’s side. Because the pursuit is a straight race, there’s no factored time. Essentially, C1 and C2 riders are being allowed to compete up a class(es) at the C3 level for this event.
The 500m time trial should have factored times for the different classifications like in cross country skiing, since the result is purely a matter of time against the clock.