Many thanks for reply! Yes, I have read the stuff at the link, but there is: “Sometimes it happens that the plugins inject models that have the same name as yours.” so this is - as I understand - about conflict on model names level, not table names (collectionName) level. It looks like what is described there is default behaviour of Strapi to prevent naming collisions during plugins/models generation, which is perfectly understandable. In my local plugins my models’ names would be different, and I could change collectionName in both models definitions to point to the same table. My concern is, that Strapi can track plugins/models/collectionNames logic and if not now, maybe in near future, it would cause business logic bugs difficult to fix.
HOWEVER, the above approach would mean separate models schemas, which may lead to mess sometimes - one model schema updated, but, the other one not. So, I have just checked that from one local plugin I can reach model in the other plugin, which is sufficient for my purposes. And, one model schema per one table looks more safe.