Production data and first royalty check

first well started production in July 2013 then 2nd well started April 2014 yet my cousin tells me his first royalty check was nov-dec 2014 range. that timing sounds proper for the 2nd well but I cant figure out why checks would not have been sooner in association with 1st well. these wells are not right next to each other. different names too. my cousin has also indicated the division order came January 2014 or so. I got a family set-up where they all seemed to just sit and wait for checks but don’t pay any attention to data… the wells are 9 months apart yet the first check wasn’t til 15 months from first monthly production according to drilledge graph ?