i'm not for sure. of the all the Presidents only a little over half have held military positions. John adams our second President never served. and there was also a period of 6 Presidents in a row who didn't serve.

DO I think them having military service will make them a better President. maybe in matters that would relate to that. but as to the econmoy or labor or trade. Overall No

Would the founding fathers have made it manditory. yes probably. This country was founded during an uneasy time basically during battle.