I get confused by the SMI/SPI/SLI naming. I think all of them have the same issues regarding size occupied by Nestle, Novartis, Roche.
The Magnificent seven in SP500 is also bad, but at least it’s 7, not 3. But it’s anyways not suitable for the home bias 
7 out of 500 
3 out of 200
Right, for SPI extra, UBS and Swisscanto index funds are the only options, as far as I know. You can invest in those at Swissquote, VIAC and finpension.
However, there is an ETF tracking SPI Mid, which doesn’t include the smallest companies but may be close enough.
Interesting, is this the main reason to overweight swiss indexes? How big is that expected benefit from a total return perspektive?
Nah, this benefit is overrated. There are other countries that don’t withhold dividend taxes. And, e.g., US does, but the dividends are so small that you usually end up losing way more taxes on Australian stocks (because Switzerland is still going to tax you).
Actually, not really. CHDVD includes only about ⅓ of the SLI and adds another 9 title that are not included in SLI. So overlap is only 11 of a total of 40 titles.
But you’re right in a way that one should probably decide to use just one of those two. I have both because I couldn’t decide
That’s what I do for 4 years now. I have about 20% of my investable asset in SPI Extra and 5% in SMI. After years of undeperformance returns are ok now.
Anyway I’ve made a quick analysis of the index constituents and by a rule of thumb it doesn’t seem that “Swiss oriented”
-10% of the index is making above 90% of business in CH (Cantonal banks, VZ, some microcaps)
-90% of the index is making about 10% in CH
So total might be around 20% business locally. Still better than overconcentrated SMI but still questionable.
I see this investment rather than a medium/small cap tilt and diversier of VT.
I would not think of number of titlles but % weighting overlap, and that is very huge here.
And there overlap is roughly 50%.
Top 10 holdings of CHDVD are also 92%, so the other 10 stocks are basically meaningless. It’s extremely concentrated. SLICHA is quite concentrated as well though, at 62%, but still meaningfully less.