Noone can tell you that.
Everyone is spending their time and energy to get the best bounty.
also it depends on various factors , how many stakes they give to your rank in respect to higher rank
Yes its true, as bounty hunter you should doing your own research and find the best signature that you think good for you. You might get an answer about signature from stranger but it might not be good one cause out there there is so many new ICO that started the bounty and many are not success to reach the hardcap.
I think it would be best if you can find it by yourself