Stoicism shares a lot of parallels with Buddhism in its approach to detachment and focus on so-called virtuous behaviour.

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My issue with Stoicism is it quickly becomes bent into a kind of tough guy, cold, emotionally detached approach to reality.

But isn't that missing three core concepts of Stoicism then? That one, concepts like compassion and generosity are in and of themselves virtuous behavior. That two, detachment isn't about separating one from reality but a way to live with it. That three, deeds matter?

The problem lies in whether or not self-restraint and possibly self-denial is appropriate in all contexts, and to what degree.

Detachment isn't about self restraint or self denial though. Detachment is about the ability to let go and to not be moved by undue influences. For example, I love my car but if I crash it and total it, I need to learn to be okay with that or else the love of my car will harm me. Or I love and adore my country, but I need to exercise that love and adoration with detachment so that I am able to see its flaws and protect myself from falling into a jingoistic mindset. Detachment doesn't mean I can't own a car or love my country or hope for good things, detachment means I need to keep those things from corrupting me, harming me, or cause me to harm others.

The other problem is it is very difficult to truly know what it is or isn't in one's control. I could spend the rest of today writing a song, call a random drummer in a Facebook group, work like a dog, and have a music video out by next Friday that will propel me to international stardom. Is that likely? It's possible. I would argue to desire anything seriously requires a degree of attachment, and potential disappointment and unhappiness. That doesn't mean you shouldn't still do it.

Once again, detachment empowers you to do your best, hope for the best, expect great things, but be at peace with the results if they're less than stellar or if they are stellar, keep the results from going to your head.

Edit: I'm not trying to be argumentative or combative here. I'm just trying to sound things out loud because the way you're talking about stoicism and the way I understand it feel really different.