I don't see reasons to compare Horizen with other projects. Investors can compare to make their decisions, but Horizen team should not, because they should give investors a pure overview, to choose which ones they think are best ones for their portfolios that won't be affected by comparisions made by Horizen team.
Few posts up, I started to compare Horizen with BTC. I stopped because there are so many differences (also post could be too long). Horizen is platform and there we can draw the line. ZEN is major product of this platform but not the only one. In core ZEN is fork from Zcash and Zcash is frok from BTC..In short ZEN is improved BTC.
Horizen as platform has completely different goals and tend to solve some burning problems, such as privacy, right on free speech and publishing. Alongside it is evolving and adapt to current situation and trends.
This is from my personal perspective.