Hicks: and will never give up a friend.
Yonge: and will grieve none of his friends.
Yonge's translation doesn't seem to make sense in light of the original context.
Original text: φίλον τε οὐδένα προήσεσθαι: not one friend would be delivered up to an enemy or betrayed
See the Perseus Digital Library for the definition of the key word, προήσεσθαι. So, the σοφός will not abandon or forsake a friend.
Hicks: And he will on occasion die for a friend.
Yonge: and he will be willing even to die for a friend.
Mensch: And he will brave death on behalf of a friend.
Original text: καὶ ὑπὲρ φίλου ποτὲ τεθνήξεσθαι
ὑπὲρ φίλου metaphorically could be "in defense of a friend" on occasion he will die.
This makes sense in relation to never betraying a friend. These two characteristics are listed in the following order in the original text (using Hicks):
He will be armed against fortune (A) and will never give up a friend (B).
...he will be like himself even when asleep (C). And he will on occasion die for a friend (D).
These are separated by a number of lines, but, the fact that, in my opinion, A and C seem to be connected, I am theorizing that B and D are as well. I believe each reinforces the other.