First of all I dont see much worrying, I see some concern that after taking zero rb's last year and only having 1 lined up for this year (with major qualifying issues) there could be an issues if injuries or off the field issue hit. I think that concern is extremely legitimate especially when PTG has a pretty significant injury history. You dont see many Div 1 programs bring in 1 rb in two recruiting classes, if a few players go down and Erv phillips is suddenly the #2 I think your opinion would change real quick.
Second your answer to what Mcdonald would do if we were hit with injuries at RB isnt feasible at all. This team is no where near ready to become a team that throws the ball 75% of the time. Hunt is not that type of QB first of all and second the offense is still being modified and accompanying players brought in to match the system. No matter how good KJ, Custis and Ishmael look right now there still going to be Frosh and need time to adapt to the speed and play of high end Div 1 and to learn the playbook. Syracuse still needs a potent running game to be successful, we cant become Washington State after one year.