I think there are a few things right now that J-10 is behind Typhoon on:
1. lack of supercruise
2. less stealthy
3. less advanced radar
4. less advanced missiles
5. lack of a built in IRST
6. most likely less combat awareness/weaker avionics
These are all things that can be achieved. supercruise and more stealthiness can be achieved with the next J-10 block (using more powerful engine and improved aerodynamics). Radar can be upgraded. People all talk about AESA radar, I really don't think China is that far behind if you look at how many platforms in service already use AESA radar. As for missiles, they can be developed. PL-8B has been in service for a long time and we know that a new generation WVRAAM has been in development. We also know upgraded PL-12 and long range AAM are also in development from previous interviews with the developer of SD-10. As long as you are willing to pay more money, you can get more advanced missiles and radar. If you just look at the number of PGMs and stand off missiles revealed from last November, it's really astonishing. Nobody thought China had that kind of ground attack strike inventory until that point. J-10 right now don't have IRST (although it can be equipped or carried in a pod), again this takes up space. If you really want it built in, it can be with an export version. As for improved situation awareness, additional avionics like towed decoy and other things, they can also be developed easily. You have a very good platform in J-10 that rivals typhoon/rafale in many flight performance category. It won't have the same payload/range as the other two, but it can be in the same league as far as air combat (especially once the first upgrade block comes along).
And once the twin-engined J-10 comes out, I don't think we'd be comparing that to typhoon. There is only one ultimate mission for it: that's to be able to defend against F-22/F-35 on Chinese soil.