Obviously you have to make sure that you are close enough with your jump in that you will be getting Oro’s close st. mp instead of his far st. mp. The other thing is to make sure that you are hitting deep enough with your jump in attack to be able to combo.
You can start a jump in combo with just about anything- hk being the go-to standard, mk if you want to cross up, mp for variety and fierce punch rarely when you’re feeling frisky and on taller characters.
If you aren’t punishing, you’ll want to confirm by doing (for example) a hk jump in cancelled into st. mp (two hits), then your follow up of choice if that hits. Alternatively you can do a jump in hk to stand mp and superjump cancel the first hit of the mp for a semi-safe approach. If it’s blocked you’re in the air to escape or continue mixups, if it hits you can get a jump hk in.
Never just straight up go into the chicken combo without confirming. It’s wildy unsafe and even average players will be able to punish hard.