Possible Clues:

• Back of the train there in front of the army
• 'Back of the train but front of the attack there (2,3,3)'
• Ahead starting off 9th, then all square, with Koepka finally besting Europe's No 1
• Leading (as goods may be transported?)
• Back of the train, front of the army, there
• In the head of the army but the tail of the train there
• Travelling at the front
• Front of the army, back of the train there
• At the front of the army, at the back of the train (2, 3, 3)
• Fighting in front of the back of the train