I would like to leave the field name the same in the primary tables
Don't understand that statement - if you were to move the memo fields to another table, that field would no longer contain data in the original table, so the queries wouldn't work as intended anyway.
Regardless, I've used memo fields (only as required) for many years and cannot recall any corruption of them, but that might be due to how I used them**. IMHO, you're more likely to experience corruption through practices such as altering design on an active shared database, forcing shutdowns with Task Manager, network hiccups, etc., which is why regular backups are important. It would be enough to move the memo fields to their own table in the same backend database if that provided some level of comfort. I see no compelling reason to move them to an entirely different db. What I would never do is link memo fields between tables or attempt to sort on a memo field in a query. If sorting is a requirement, you should add a calculated field to the query, sorting on the Left(n) characters of the same memo field without showing it in the form or report results.
**I did not allow the memo field to be continually edited/appended to. For example, if successive comments need to be captured during a work phase, it is far better to capture each comment in a table of comments where the comment field is a regular text field, all the while capturing the date and user id of the writer rather than append to a memo field and losing edit history. Even if I needed a memo field for this, my approach would be to not repeatedly append to it.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.