This was a trilogy of books I read 15 years ago in high school. What I remember is fairly fuzzy, but any help would be great.

Set in the future - space travel is commonplace

Something about star whales

Mercenary companies are/were widespread initial book follows the story of the commander of the Iron Legion - fairly successful group - has an archival group but I don't remember their name - now the groups are being pushed out of business by "government"

Leader of the iron legion captures one of the commanders of the rival group and keeps him locked up in a room with a machine that slowly skins him alive - I think the guy killed his wife?- guy escapes and the two groups fight a battle - both are wiped out by a nuclear weapon

Commanders son ends up with the "government" military as a brainwashed assassin - can psych himself up to go all deadly killer like, but it takes time and someone he knows to talk him back down.

The only other thing I remember was something to do with the clarinet - commander played it - really sad song

I know it's not a lot to go on, so any ideas would be great