I will attempt to put this as simply as I can.

Any historian, right, left, centre, published in popular bookshops or newspapers or the Internet paint A picture of WW1 not THE picture of WW1.

Most people accept this and glean information from it. Most people do not accept as "Gospel" the things that are written.

We apply the knowledge we have gained from other books and treatises and deal with the new information accordingly.

We do not accept that the particular historian is 100% correct, we apply a degree of logic to the things we read.

Thus when one person says THIS historian or THIS group of historians are correct we look at the other information we have gathered and think perhaps the TRUTH is somewhere in between.