Rav Hirsch stated that the more the community pressured everyone to think alike, the more the people resisted and tried to follow their own way of thinking. Hashem made the miracle of forcing the actual change in language to follow these ways of thought in order to have it happen so rapidly. Rav Hirsch does not deal with archeology or anything else other than the meaning in his commentary.
When they were one community, then trying to make a name for themselves was an attempt to rebel against Hashem and replace Him with the head of the government. Once they were dispersed and speaking other languages, then even if each one individually, tried to make a name for itself, it would not be an attempt to defeat the purpose of filling up the world, but would instead actually cause a further dispersal into multiple civilizations.
Note that I.L. means that the translator (the grandson of Rav Hirsch, Rabbi Isaac Levi) added an explanation to the translation of Rav Hirsch's commentary.
Rav Hirsch says that the pasuk means
"Safa Achas" means the phonetic sameness of speech (the sound of the
language I.L) which is fundamentally based on organic causes. "Devarim
Achadim" is the sameness of the formation of words and sentences which
is brought about by spiritual mental agreement in the way that things
and their relations are looked at.
Rav Hirsch points out in Noach 2:7, that the words used for matters like "justice", "virtue", or "charity" in different languages can have completely different connotations. It would appear that even though everyone thought that they were speaking the original language (from the time of Adam), Hashem changed what they were saying to have the connotation that they really wanted and made them into the differing languages.
For example, think for a minute that the word to "have" was missing
from our vocabulary. In Hebrew it does not exist. "To have" has the
conception of corporal holding fast, "habere", "avere" to desire
something, and when one has seized it, then one "has it". Let us
imagine that this conception was not there, a man could only consider
that to be his which really appertains to him, like לו in Hebrew. ...
Then the first person who introduced the idea of "have" (I have it,
whether or not it pertains to me or not I.L.) would indeed have
brought about the greatest revolution; he would have changed the idea
of right to the idea of "grab".
...
The attempt by the community by this building to do away with the
individuality of the individual was broken by the awakening
consciousness of the independent value of the individual, apart from
his value as a unit of the community.
So that the disunion did not arise out of a number of languages but the
other way round. It was the discord which first begot the
disruption of the language, so that at the beginning, the Safa Achas
could still have remained ... without the climatic change, even before
the scattering which ensued in the safa achas there was no longer
devarim achadim. This variance in opinions drove people completely
away from one another, where then the climactic differences of the
regions had the influence of making them and their languages
completely and organically different.
Rav Hirsch points out that normally these developments would take place over a long period of time. However, Hashem caused them to occur almost instantaneously so that the entire development of the "Migdal Bavel" would collapse and cause the immediate dispersion of the various peoples.
