DISCUSSIONS on “Rules for online games in HoMM3 and formulas for calculating player rating.”

Sure, you can. For example, I played through it with Stinger.

On all templates, except for the XL+U size templates:
2.6.1. To pass from one zone to another through a specific passage, it is necessary to eliminate the guard of that passage. If there are several guards at the passage, it is enough to destroy any one of them.
2.6.5. If there is no guard at the passage, it is allowed to freely move from zone to zone.

so, that means tech loss if the map is a CMK map.