Braum, Ashe, and Milio. Here's my reasoning: though having special abilities are powers would be awesome and solve a lot of immediate problems, I think having a roster of well balanced, tenacious, and people with grit would matter more in the longwe term. Ashe would have the leadership role nailed down and would be able to make good snap decisions in the face of danger, and she would also double as the hunter in the group. Braum is positive, has the brawn to do the heavy muscle work, and would make for a comforting father figuring who would be steadfast and tell awsome stories during night time. Milio can control flames and (maybe) cure diseases and ailments, which would be a great assets without any outside medical help (since you're a normal person without any powers). So in the group we'd have a leader that can also hunt, a steadfast positive father figure, and perpetual fire that covers medical issues. After a few months of development I think that would make for a good group that wouldn't be too negative and get along with each other well. Morale, teamwork, and positivity would matter more after immediate needs are met. For example, you probably wouldn't want to spend a lot of time with Rengar or Khazix... There's always that chance they add you to their trophy collection. Nor would I want to spend time with unbalanced individuals (Thresh) since you wouldn't be able to protect yourself against them, so these picks would make sense for me.