In the famous Caesar's sentence:
*Perfacile factu esse illis probat conata perficere, propterea quod ipse suae civitatis imperium obtenturus esset: non esse dubium quin totius galliae plurimum helvetii possent: se suis copiis suoque exercitu illis regna conciliaturum (esse), confirmat. *
The first illis in Perfacile factu esse illis probat is ok and easy. The problem is with the illis on se suis copiis suoque exercitu illis regna conciliaturum (esse), confirmat.
To me, that second one shouldn't be on ablative nor on dative but on genitive. Can somebody please make sense of whatever case it is in that sentence?