By Nick Robson & Ashley Iveson & Alex Richards Gordon Elliott again was left unable to do anything but praise “thorn in his side” that is Willie Mullins, after Delta Work found only I Am Maximus too good in the Randox Grand National at Aintree. The two powerhouse trainers have long matched strides at the top of Irish racing, with Elliott having to settle for second in the Irish trainers’ championship on multiple occasions as well as on some of the biggest of British stages, including when Gerri Colombe chased home Galopin Des Champs in this year’s Cheltenham Gold Cup. Elliott fielded seven in …