I think you should re-evaluate what you've done first. Why are you ditching your old strategy? Are you losing patience, losing confidence, admitting failure or really think you can do better with a different approach?
Tech/a often mentions the "beginners loop" (or something to that effect), where a new student in technical analysis change his methods every so often because the previous one didn't work out. They do back test and find new kickass indicators and re-write their trading plans and improve the expected expectancy on paper... yet in the end the new approach would fail again, and the trader goes back to square one and start all over with new plan, indicator, signals etc etc.
I am not saying that is what you are doing... but I can see the parallel. So it's up to you to ask yourself the honest and hard questions. Your portfolio underperformed XJOAI by 30%... that is not good. I bet you if you are up 30% you won't be looking to change strategy.
If you are admitting failure... then sure, sell up and move on. But you should also lookback on why the strategy failed.
If you are losing patience... then I'd say stick with it. If your initial plan is indeed a 5-year (or however long) one and you are only 2-years into it... then you are doing yourself a dis-service by ending it prematurely. May be trim a thing or two that no longer fits your criteria today. But you are not allowing the strategy to work itself out in the fullness of time.
If you are just losing confidence... then stick with it and change nothing. We all lose confidence in our ability at one stage or another. It's no reason to change an otherwise correct course of action.
If you really think you can make better returns using a different approach... I'd test that assumption again. Will you have the patience and committment to stick with it over the intended timeframe? I'd also check and make sure that the return from your new approach is going to be better than the current starting point (namely, start of year 3 of a 5 year plan).
Only you can answer these questions.
Gee its nice to see this post. Some important considerations well put. I wrote basically the same thing and then deleted it because I don't have faith I can communicate well enough on these types of hard questions even though they should be asked.
Only other point I had in my deleted post was that if moving on is the right answer - then I think you probably should sell all immediately. I think being a strong hand in the market is very important if you are not going to get shaken out at the worst of times - you can't be a strong hand on something you are unwinding to move on to something you believe in more. Don't need to be a strong hand if the price is moving in your favour so maybe consider some T/A to time the exits of of any stronger stocks at the moment, but consider your reaction to possible gap breakdowns of a trend if you go that way.