Hi
3700 apears as subordinate only on Cisco doc:
https://www.cisco.com/c/en/us/td/docs/wireless/access_point/mob_exp/83/user_guide/b_ME_User_Guide_83/about_mob_exp.html
Master APs
Cisco Aironet 1830 Series
Cisco Aironet 1850 Series
Cisco Aironet 2800 Series
Cisco Aironet 3800 Series
Subordinate APs
Cisco Aironet 700i Series
Cisco Aironet 700w Series
Cisco Aironet 1600 Series
Cisco Aironet 1700 Series
Cisco Aironet 1810W Series
Cisco Aironet 2600 Series
Cisco Aironet 2700 Series
Cisco Aironet 3500 Series
Cisco Aironet 3600 Series
Cisco Aironet 3700 Series
-If I helped you somehow, please, rate it as useful.-