The Kwarizmian cavalry are not available until 1200 because of the heavy armour they wear. If you want them to be available earlier you have to remove the 'and event_counter HEAVY_MAIL_ARMOR 1' event from each entry in the EBD in the 'mods\conquest\data\970' and the 'mods\conquest\data\1080' folders. For example you would change:
Code:
recruit_pool "Kwarizmian Cavalry" 1 0.34 2 5 requires factions { northern_european, eastern_european, southern_european, greek, middle_eastern, } and hidden_resource asia and event_counter HEAVY_MAIL_ARMOR 1
to
Code:
recruit_pool "Kwarizmian Cavalry" 1 0.34 2 5 requires factions { northern_european, eastern_european, southern_european, greek, middle_eastern, } and hidden_resource asia
As the Khwarezmian dynasty didn't exist until about 1077, they were a vassal of the Kara-Khitan Khanate until 1194, they conquered the Great Seljuk Empire in 1205, and they didn't act as mercenaries until after the Mongols destroyed the Khwarezmian dynasty in 1220 they shouldn't be available at the start of the 970 campaign. Strictly speaking the Kwarizmian cavalry should only be available at the start of the 1200 and 1230 campaigns.