Logically speaking, bringing in the unknown soldier who was clearly not in his best state was not the best idea. It was a bit of a gamble, and one that was more likely than not going to end up in the soldier's demise. Nero had no delusions about that.
Unless he composed himself, or displayed capabilities beyond the norm, then facing the berserkers his demise was all but written.
But at the same time, this was his own decision. In the face of death, he wanted to resist. If Nero denied him this opportunity, he might continue to live, but the shadow of this memory would haunt him forever. Perhaps, then, that would have been a death of another kind.
But there was no point in speculating. What could have happened if they made different decisions was a pointless thing to contemplate, unless one was trying to learn from their mistakes. What mattered right now was that, regardless of the outcome, the soldier had a resolve that Nero chose to acknowledge.
