Yes of course - losing to Berdych 4 times in a row, spread across about 6 years, will invalidate all of Murray's other consistent and commendable achievements. I don't think Federer should be considered a part of the big 4, as he lost to Guillermo Canas at both Indian Wells and Miami in 2007.
Did I say that losing to Berdych for a 4th time in a row would cancel out his efforts so far? NO but it would indeed go some way to increasing the confidence of other guys in the top 10 that it is the big 3 and the rest with Murray the best of the rest rather than part of that elite group himself!
Besides while the first loss to Berdych was 6 years ago if Murray loses tomorrow that will be 3 losses to the Czech man in as many years and including a beat down in a major.
Fishy also beat Murray 3 times in a row in 2010, Pretty poor comparison seeing as Roger won 3 Grand Slams that year which are the pinnacle of our sport, how many majors has Murray won then? I will give you a clue it is 16 minus 16 :-)