Hi there. It sounds pretty normal to me
I sometimes wonder what to do with the enormous hoards as well. I don't think it would do any harm to reduce the amount slightly from underneath
As your hammy is quite new he is probably still a little but anxious that there may not be enough food one day so he is stockpiling lol. Once they get more relaxed and recognise that food is put out for them all the time - he may hoard a bit less. Always leave most of the hoard if you can or he may start peeing on it if he thinks someone is stealing it! But reducing it slightly from underneath could be a plan. As long as he is happy
As CMB says maybe put slightly less in his food bowl each time - but enough that he doesn't think there will be a shortage! I find the more food I put out, the more he hoards! If it's there, they will hoard it. I put about a tablespoonful a day out - put half in his bowl and scatter the other half in his cage - they have fun foraging for it.