[LDiCesare]

Your supposition that someone would send grendelkins naked anywhere is astounding.
Did you actually use some grendelkins, fully kitted, and use them with success?
I kitted some of them fully, and they performed VERY badly.
I will not waste water gems on them, because water gems are better used on getting underwater, with troll kings for instance.
If I want an SC, I'll stick with Tartarians. They are cheaper and pften have useful magical paths, don't need as much in terms of elemental resistances or reinvigoration, are neither much harder to research nor to cast.

Did you actually use them in some game? Did they perform well? Were they cost-effective? How do you feel that they can't swim? Did you try to send some of them underwater just to see how they crawl down there to the point of being unable to even reach their opponent before routing and dying?

And please don't insult people.