I'm sure you are able to split your infrastructure in any way you prefer to avoid this issue.
Also, probably, the best way to manage problem like this, is pay 1 block every type of mining present ( party, everyone, solo ) if some miner ask you why after more than 2 week at 240M is party mode with 2 miner (4 total miner in party) and 26% of shares each miner, he received ony 2 dgb.
In this case, where probably you have to pay more than what you mined, for sure you review your data and been able to understand and solve the issue, and , pay the right amount on right miner.
But i'm not here to suggest you how to build your pool, you are pro so you know how to do.
I'm only here to say: i never read this fantomatic rules, so probably is better to write on top of your pool "if something goes wrong on my pool, sorry! i know it happen, i don't know how to fix, so everyone take something".
Because that's what you are saying now.
Else, like other pool, after one issue you can write:
" Sorry! there was one issue on my pool and i'm working to fix it. If you loosed something due to pool issue, write me a msg and i try to solve it"
In this way every miner is sure don't waste his time.
Yes, block found by zergpool.com hash, but it does not mean it was found exactly by your miner, as obviously many miners contributes. If wallet daemon RPC got stuck(due to respective coin daemon issues) and we are unable identify miner, and we are not taking reward to our pocket in this case. But giving the best effort to reward miners in case issue, and distributing equally to everyone - seems to be the appropriate at this point.
Please suggest another approach, I will be happy to implement, but currently we do it this way and report wallet issues to respective developers hoping for quick fixes from them.
Hopefully it give some clarity on underlying process.
pinpin