Explain to me how who goes 1st on Fleet Arena works?

Except you're getting confuse I think.

If anyone one turn is 50/50 (it's not), then sure, at any point in time any individual flip is 50/50. However, the probability that you go first 0/10 times should be equal to getting 10/10. It flat out is not.  

It's exceedingly low probability to go 0/10. Yet, i'd wager most people have seen that. I'd wager extremely few have seen 10/10.

After the tie dagger switch, i counted mine the first 10 days. I hit about 15% of going first. That's not a 50/50 chance.  To date, you can't find that it's 'balanced out' either.