Union All of one linked server in a With clause of query of one linked server

In a stored procedure, I have a few With clauses, of a query executed at linked server A:

DECLARE @myQuery VARCHAR(MAX)

SET @myQuery = 'SELECT * FROM (WITH 
   A AS (Select ... from ...),
   B AS (Select ... from ...),
   C AS (Select ... from ...)
   Select A., B., C.
   From A
   Join B On
   Join C On
')


INSERT INTO Table_A
EXEC (@myQuery) AT Linked_Server_A

Now I want to Union All a query executed at linked server B, with same structure, in the With clause B. It shall look like:

DECLARE @myQuery VARCHAR(MAX)

SET @myQuery = 'SELECT * FROM (WITH 
   A AS (Select ... from ...),
   B AS (Select ... from ...
         UNION ALL
         Select ... from Openquery(linked server B, 'Select ... from...')),
   C AS (Select ... from ...)
   Select A., B., C.
   From A
   Join B On
   Join C On
')

INSERT INTO Table_A
EXEC (@myQuery) AT Linked_Server_A

I would like to know if there is a simple way to achieve this. Appreciate for your feedback.