As someone who trained firstly as an archaeologist and then at post-grad
level level as a historian I have to say that most historical work by
arcaheologists in Europe and the US is of very low quality (though they don't
know it) At the level of basic CRM assessments you hardly need a PhD
historian though i do plenty of this myself- and I am a lot quicker than most
of my colleagues. However, the more in depth the research the more 'la
difference' shows. The most common errors are misunderstanding sources, not
finding out of the way sources and poor grasp of important areas of knowledge
such as legal history- boring for most of us but very necessary. At least
most of your sources in the states are in english -I once spent a day
searching for a published reference by a very famous arcaheologist to 10 elm
trees built to repair a mill. I later realised it was the same reference that
I already possessed to buying 10 ells of cloth to repair the mill sails.
Archaeologists should realise that historians come in all shapes and sizes.
economic, social, political, theoretical, anti-theoretical, friendly and not
so. The best documentary work in world archaeology has probably been that
done in England in the 1970s and 1980s by trained and "exceptionally
talented" historians working full-time in local goverment archaeological
units (now a thing of the past) by the likes of David Roffe and Derek Keene.
Long term US preservation projects have also produced some pretty stunning
historical work( eg. Lois Carr's work at St. Mary City), though perhaps less
good on inter-disciplianary integration or this just a reflection of
publication. I also think to us a jolly good thing for archaeologists to get
a decent historical training an do historical research themselves- it gives a
different perspective. However, this takes a lot of time and committment but
I can only say I am impressed by the work of anne yentsch and mary beaudry on
documents. However, it is 25 years since I read my first latin primary
document (and more since I picked up a trowel-I was a youngster!!!).
Nevertheless,  I feel I have only just about grasped the basics of doing good
integrative work in the two disciplines. Reading a few maps and a deed or two
doesn't make you a historian anymore than learning to use a shovel (and lots
of professionals on both sides of the Atlantic can't) makes you an
archaeologist. It is also a skill to work with historians as it is with
environmental scientists and finds specialists. All aracheologists benefit
from knowing something of the work of specialists- they all need keeping on a
leash sometimes. I would three things mark the outstanding archaeological
report 1) an ability to write in concise and readable English (or whatever
language), 2) an ability to place the site in wider context 3) an ability to
integrate specialist reports into the overall story. Unfortunately these are
rare skills (especially the latter) in combination.