This isn't really the case, its more that the Crusaders were an endless tide of religiously motivated semi-nomadic pillagers that descended upon Anatolia and the Levant. They were effectively a check on Muslim expansion in the region as a Christian antithesis to the nomadic Turkic armies of the period.

The Crusader counts were constantly betraying each other, and the Byzantine forces under Alexios Komnenos. Their heavy cavalry often won the day if they could actually get in close. Otherwise, they were prone to charging in recklessly and getting ambushed.