Bowers Dates and the Tubegin School

Gospel dates proposed by even liberal scholars were walked back towards the first century. One reason is that bower's initial hegalian premis of thesis, antithesis and synthesis has been challenged. Another reason for challenging bowers dates is that we have the writi s of saint ireneus of leon who wrote around ad one 80 to one 90. Yet irenaeus is adamant that all four gospels, matthew, mark, luke and john, go back to apostolic times. So how likely is it that irenaeus would be mistaken about this? If the gospels were being written in his lifetime.