The probate records are on Ancestry, wills and probate section, Michigan wills and probate. It appeared that at least some of the property had a mortgage on it at time of Mathias's death and then administrator mortgaged more and also sold personal property to pay estate debts including farm mortgage payment & also himself as administrator.
My interpretation was Harry was paid to do certain things on mortgaged farm and whatever profit after mortgage payments was split 7 ways. I did not find a will, so surmise Michigan law determined distribution. There were very nominal dollar amounts distributed to heirs, perhaps reason 2 sisters requested different administrator...or perhaps it was because the probate file was open for several years. You would need track real estate property ownership to see if farm properties were ever split between the heirs or sold outright.
For the ancestry search engine to find probate...I put only Palmer last name, location Tuscola county, Michigan to get Palmer probates. There are a couple of other Palmer probates you may wish you read through & see if any clues to relationship.
Land records might also be on Ancestry. Or check on
Search - BLM GLO Records
I saw some reference on Ancestry inquiry board to Bird relatives immigration to US...I do not know if other Palmer's immigrated also.