enable + gerund in your first example is correct. enable + object + infinitive in your second example is correct The main difference with your second example is that there is a direct object, "them" I don't think you will go far wrong using these 2 examples, with and without an object, as your pattern

AAAA accurately x enables positioning the models in a real environment.XX >AAA is able to prove the working of his models in a real environment. BBBB enables them to take advantage of any opportunity that comes their way.OK "enable (subject) to VERB " > Enable (him, them /us) to go/eat/fly ,etc. "enable doing" X Enable(the) gerund noun/noun > He has done a lot for the country, so much so that it enables THE COUNTRY..(noun) / AAA has come up with a new model that enables THE ASSEMBLING of parts easier.(gerund noun)