Okay here we go:

• 3x Baboon ($30) - Forward ground assault and combat units
• 1x Chimpanzee ($10) - Intelligent and adaptable field commander. Can fill battlefield roles where needed.
• 1x Aye-Aye ($10) - Night reconnaissance and lockpicking. Also my favorite on this list.
• 2x Grey Langur ($30) - Divine spellcasting and healing.
• 2x Howler ($20) - Arboreal recon and comms.

If Patas monkeys are allowed, switch as many as I can for one of the Howlers. I spent way too much time on this.