No limit on the number of entries in the portfolio but 8-12...

No limit on the number of entries in the portfolio but 8-12 cornerstone holding where large capital is at risk sounds about right. These are the positive Alpha in my portfolio. The only real limit I have is that I hold 30% of the portfolio value in cash. I'm way above that threshold at the moment after recently solidifying profits on CBA and a few other holdings.

The rest of the holdings outside the 8-10 cornerstones are risk free ex-cornerstones with no holding cost. Which consist of stocks that has returned all my investment in dividends, free carried or combination of both over the years. In the last 20+ years, these negative Alpha stocks have outnumbered the cornerstones in the portfolio close to a 3 to 1. I hardly read their quarterlies or care much for their performance most of the time. The only time they leave the portfolio is if they get bought out like OZL is soon to be by BHP. Notable ones in the past are CCL, BIN, VRL, Toll etc... The sizing on these are pretty small. AZJ one of the largest weighted negative Alpha stock is only 1.5% portfolio.

If I see a good TA setup or using your words "special short term opportunities" on a cornerstone or a negative Alpha stock then I will trade for a free carry

Over time, you end up with a pretty decent looking portfolio that can ride out whatever Mr Market throws out. I understand that above might seem a lot but if you really think about that's only 2 really good investment a year for the last 20 years. Wash rinse repeat...