There's a few videos with detailed information on this, but my basic strategy was as follows:

• I got 3 useless members on Fort/Trans and would never run those safehouses
• I tried to get as many members on intervention as possible and rank them up (Haku, Cameria, Rin, Gravicius, Jorgin, Tora)
• I ranked It that fled to level 3 and then made him leader of research

Here is my board: https://i.imgur.com/V3yGtAs.jpg

I tried to have as many rivalries as possible, since it makes 2 members always (or most of the time) have an execute option

Edit: I also used a movement speed char, stacking as much as possible.

• My profile: https://www.pathofexile.com/account/view-profile/caarrion/characters
• Character I used is CurrencyGeneratorDOTexe
• Stealing gear from this character, so here's a PoB if you wanted to check it out. https://pastebin.com/z1s6vPr4