welllllllllll...
you weren't level 9. so of course you were still having trouble finding tier 4's.
your problem is that while building your composition you were building what you wanted and ignoring how the game works.
if you want to build this brawler comp of yours then you should probably build it with rerolls earlier on to give you a higher chance at getting tier 3 warwick, elise, and reksai.
because you're less likely to get any of them come mid to late game. at level 1 and level 2 you are guaranteed to only get tier 1 and tier 2 champions in your pool. from that point onward to level 6 the game starts adding in more champions to the pool and that causes it to become less likely to give you tier 1 and 2 champs due to distribution. Then at level 7 the game starts filtering out more and more tier 1's and 2's to leave you with greater chances of find tier 3's 4's and 5's.
with that being said since you said you had 50 gold and you spent it to reroll at what appears to be level 8? then you didn't spend it at the most optimal time which would have been pre level 6 and post level 9.
also your composition has a lot of issues. 1 of which is that you have a ton of HP on champions and there are items that deal %max hp in damage. also that HP is pointless against high damage/fast attackers. You deal a ton of spell and attack damage assuming you put the right kind of items on your champs, but have no crowd control since you dont have 
and all of you damage dealers minus sol and swain are melee attackers.
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the most HP i've seen on a chogath is like 6k. khazix can deal 1.5k damage. if your chogath is just a big ball of hp then he's going to die just the same as your other champs. HP is only good as a secondary stat.
i'm going to be 100% honest. i'm surprised you even made it to 6th place. especially since almost no one has any mages on their teams. i see 2 players building ninja/assassin, 1 player building imperial/noble/pirates, and 1 player building whatever they get and it's gotten him/her 4 level 3's and another player building "knight's and".
so yeah... hope this analysis of your build helps you in some way.
with 
But he was lv 1, easily killed by 1 assassin who could get a lucky crit. Even with positioning and other units to bait out them out.
and 
