Depending what you wanna achieve, you're best to take the losses yourself in bronze until you're more well established - usually I'd payout between 115-125% of what I got in bronze to entice and maintain decent membership - I would calc is based on [flat amount per OHit+Assist] then split the remaining proceeds in two and split it by both war res and hit contribution (personal res/total res + personal hit/total hit), not a perfect solution but the best way I found was fair, usually I'd only lose 20-50m/war, which I simply took out of my own pay to make it easy
If you're looking to make a profit you'll basically have to exploit your noobles while in bronze, esp with ched destroying cache prices (and they haven't found their natural equilibrium yet)
If you insist on keeping flat payouts, keep it higher and take the losses, if you can make it to gold you'll start making a profit on wins and lose on losses, but that's your best bet - I don't have BSP right now to check your stats but I doubt you have the level holders to have a higher hidden rank unfortunately lol
As a rule of thumb for sub-100k facs I suggest budgeting 100m/person/month in expenses (which you'll wanna come out of some combination of OCs, wars, and your own pocket), which would cover the basics+bribes to maintain peeps (inc war and chain prizes, which you should be chaining 3-4 times/day outside of wars if you're trying to progress the fac) and the daily stuff like beers [or higher teir alcs should you wish]/candies/meds - ofc when making the budget sheet you'll wanna add your own expenses on top (inc increased rehab costs from no tol) as well as any upgrades to your armoury you're looking into (rw gear mostly)