I suck at CVS2, but I play team Daigo too (most of the time nowadays), so I’ll try to help.
With Ken vs Yamazaki, use Ken’s max range neutral standing roundhouse a lot. At that same distance, mix it up with RC short funky kicks. Stay right outside of Yamazaki’s own standing roundhouse (this is really hard, I know :mad: ) and try to get him to jump. If he’s in C-Groove, use a fierce DP as anti-air. If he’s in K, use a jab DP which should be safe even if JD’d. If it is JD’d, you can try walking under him (if he’s high enough) to the other side, then short, short xx super when he lands. Other than that, roll through those long range serpent slashes (the ones that hit at your feet and your face…sorry, I don’t play Yama) and use Ken’s quick dash to your advantage. Try dashing right next to him, then throwing Yamazaki. If he jabs you or pokes with standing roundhouse on reaction to your dash, try dashing and busting a fierce DP. It works more often than it should. Use RC strong/fierce fireballs from that spot right outside Yamazaki’s roundhouse. If he starts reflecting them, get ready to roll through and short, short xx super.
Here’s a cool crossup I found with Ryu and Ken a long time ago: after a fierce throw from midscreen, superjump toward your opponent’s body as soon as they hit the ground. At the peak of the jump, do a roundhouse hurricane kick. You should land directly behind them as soon as they rise, then do short, short xx super if they block incorrectly. You can mix it up by doing a short hurricane kick instead, and landing right in front of them. Of course, delayed get-up and safe fall might fuck this shit up, haha.
With C-Ken, mix up your anti-airs with an occasional air-to-air superjump roundhouse and also his airthrow. Airthrows work well against K/P-Groovers that like to bait and JD/parry anti-airs.
Hope this helped!