It looks like you had a fine team comp there, hard to say why you lost without even more info. It looks like there were a few others that also went partial Wild comps above you and they probably absorbed more some of your potential. My understanding is that there are a limited number of each champion in the game and that everyone is drawing from that pool. So if you have three or four people going Wild, it makes it less likely to draw those champs in your refreshes.How often do you cycle out your starting units, even if they're 2 star? I think I am just hanging on to my early units too much
Here's my ending screen for a game I just played, you can kinda see what I had.
I also find that the most useful thing for low-level 3-stars is to not actually put items on them. You want to save items for your Gnar or Aurelion Sol or Morgana/Lulu. I tend to put items on champs I intend to sell early on in the game and then transfer them over to the higher star champs as I get them. Like I might have a Rage Blade on Kass early, but I would sell Kass once I started losing and move that to Lulu or even Gnar.