Is "Warrior of Valkyrie" skill worth investing?

[Nirual]

Well combo it with trembling hammer on a lv1-3 unit and you can get more troops back than you lost...

And yes, it rounds down. But while it says "random" it does seem to always pick the stack with the most losses.

For me its more a convenience skill overall. Less fights I feel compelled to restart because I lost a lot of valuable troops by mistake.