Some of the teams are real.
Until the engine can handle contraction properly then it has to have the quasi-historical setup of AL and NL pre-1901.
Essentially the out of the box setup has some real teams for 1871 and some that don't exist yet. So you can't match the transactions to the right teams. The Middletown Mansfield, for instance, don't exist if you use create historical league. To my knowledge there is no way to use automatic real transactions unless you create a historical league and choose real transactions.