Possible Clues:

• One of three has to arrive from Dumas, by the sound of it
• Armed soldier (hist.)
• Henri Cochet was one of four
• Athos, Porthos or Aramis, say
• Sounds like one of a novel trio that just have to arrive
• This old soldier 19 across here, by the sound of it
• Athos or Aramis
• Feverishly seek term about universal soldier
• Fantastic UK esteem at resistance of soldier
• Old soldier is obliged always to protect half of county