https://bugs.winehq.org/show_bug.cgi?id=45311
--- Comment #7 from Andrew Eikum aeikum@codeweavers.com --- (In reply to Olivier F. R. Dierick from comment #5)
commit b747d6f6ccdf1699a9242a570d681fa246de592e is the culprit. It makes xaudio2 default to builtin.
The workaround is to set xaudio2_7 to "native, builtin". Does it work with Skyrim?
Many games include the redist stuff themselves, so you will still get the native xaudio2 components without using winetricks. This is why you are able to work around this by using native xaudio2_7 without using winetricks. The commit you mention means we always use Wine's xaudio2 even when a native xaudio2 is available. This is to work around Bug 38668. As you found, you can override this setting in order to use native to get the old behavior from before b747d6. If it doesn't crash for you, using native is a fine workaround.
I'm working on a fix for the Skyrim bug mentioned here. I haven't looked at Orion or FarCry 3, so I don't know if this fix will help them.