I'm sorry if I don't completely understand your question, but I'll try to answer.  If I'm answering the wrong question, please let me know :)

You cannot use the Reinforcements Tactics card to recruit neutral units; only your own faction-specific units.

aisrham said:

The cities can indeed allow you to place neutral units, but the cities are a special case.  In fact, if you choose to get units from a City using the Rally Support order, you can ONLY get Neutral units - you cannot use a city to get faction-specific units.  Technically speaking, receiving Neutral units in this way is not considered "recruiting".  Recruiting always refers to placing your own units in a Stronghold.  The ability the City grants you is similar, but the term "recruit" is not used.  A subtle distinction, but important :)

came the doubt precisely why, in letters as "reinforcements" says not recruit says wins or places the selected troop type into a fortress. so the question. I already know that they were two different terms.

aisrham said:

Strange, in my copy of the game, the "Reinforcements" card says "Recruit 1 of the following at 1 of your strongholds".  I wonder if the wording was changed in other printings (or perhaps during translation, if you are looking at a non-English copy).

must be a translation problem because I have a non-English version. then everything cleared up. thank you!