middle name dilemma

Ok, we're due in April and we decided to name our baby Jackson, after my fiances stepdad Jack. With our first son Logan, who's 2, we did his middle name after my fiance, Nicholas. Well, for Jackson's, i want his middle name to be James after my dads middle name. BUT, my fiances brothers 2 year old has that middle name. so he doesn't think we should 'copy' it. but it has more meaning for us than it did his brother. i personally don't see any issue with cousins having the same middle name. but Nick disagrees... any thoughts?