Unfortunately no, it’s not possible to run dbt correctly without calling dbt run or dbt build.
There’s a detailed reason laid out here: Run dbt without compiling. The TLDR is:
Because model SQL may be dynamically templated based on the results of a previous model, there’s no way to pre-compile all the SQL and ship it off for execution elsewhere—dbt needs to be involved from beginning to end.
You mentioned you’re using an in-house orchestrator, so I’m not sure what a solution might look like for you. Perhaps if your orchestrator supports running a docker image, you could package your dbt project into an image (along with the dbt-core package), and build your models that way.