A personal peeve I had with the wiki in its early days was that while it was informative, it was rarely instructive, the information was there but sometimes critical bits of it would be scattered across different pages and attention wasn't drawn towards those finicky interactions.
With that in mind, I'm quite fond of the current discretionary funding page, there are several peculiarities to the DF system that do not translate into the mechanics of normal ProN investments, and the current DF page explains those very well, I wouldn't like merging the DF investment into the investment page if it meant losing those details, but I also think transcribing the entire DF page into the main investments page would interfere with the readability of the later.
I would prefer if the DF page was kept, but it was addressed as an "Investment round" of its own by the main investment page and linked to, similar to how the walkthrough page treats the big war events by linking to their specific pages.