Variants

These days probably all publications of the Bible (in this case the NT) include variants in the margin, as alternative to the text printed in the body of the page. Variants between texts must have been inevitable in the days before printing. I imagine dedicated labor in the 'backrooms' of the Empire, possibly in spare time at the end of the working day. No strong lighting, etc, and absolutely no wage subsidies! However, proper account needs to be taken of the very considerable skill in the traditions and meticulous work of scribes.
The Gospels are not biographies and are not written in the way a contemporary author of our times would write. They reflect the literary standards of the first century (and after). Copyright did not exist! No concern about plagiarism. No central authorised publisher - the only multi-national business was the Empire. Sequence contained in a Gospel is not necessarily based on time but may be arranged by similarity of content. Another Gospel may have 'pericopes' placed differently. Some of the extracts are clearly compressed in one author or another. (From my post, 'Trustworthy Documents'.)

There are places where today's ancient collection includes variants with difference in meaning. These variants are noted in the margin of the translation. Working in the English, for example, I posted 'An Introduction' of a little more than 300 words from John, chapter 1, (NLT). There, footnote (g) tells us that the translators had to consider Greek for 5 other words in lieu of the Greek for the seven they used. That is a very small part of the passage, and even so, nothing critical should hang on such a phrase.

Focusing on this following example which arises from three Greek words: The NLT translators included in the main body of John 1, verse 18:

But the unique One, who is himself God,[g]
The footnote honours an attested ancient variant:
g. Some manuscripts read But the one and only Son.
The difference arises from the presence or absence in some Greek, Latin, Syriac and Egyptian manuscripts of one word (definite article 'the') and/or the replacement, in some, of the word 'God' by 'Son'.

All in all, in the selection (John 1:1-18) there are 252 Greek words, out of which just 3 words present a complicated question. There are many weighty witnesses with alternative wording. Which words were original? (The solution adopted by the publishers seems fair to me.)

Here is a conveniently brief example of a pericope in all four Gospels, as presented in the Revised Standard Version (RSV):

Textual study (margin) data was included below in each case by publisher.

As described in 'Trustworthy Documents', the final position is that 54% of the verses in the Gospels stand without any variant.  In the case of the other verses, many, many textual variants have no bearing on reliability of the record. In fact we now have before us, at the minimum, 97% of what the authors wrote. We are indeed privileged.

Scripture quotations marked NLT are taken from the Holy Bible, New Living Translation, copyright ©1996, 2004, 2007, 2013 by Tyndale House Foundation. Used by permission of Tyndale House Publishers, Inc., Carol Stream, Illinois 60188. All rights reserved.
Scripture quotations marked RSV are taken from the Revised Standard Version of the Bible, copyright © 1946, 1952, and 1971 the Division of Christian Education of the National Council of the Churches of Christ in the United States of America. Used by permission. All rights reserved.

Primary data source: Blomberg, C.L., Gospels, Historical Reliability of, in The IVP Dictionary of the NT, InterVarsity Press, Downers Grove, Illinois, 2004

Bible text accessed from BibleGateway.com

Image: author - derived from Synopsis of the Four Gospels, ed K. Aland, ed. 15, German Bible Society, Stuttgart (2013), p92