RANKX() not working over two table on calculated column

My end purpose is to dynamically look at the SUM() values of a customer based on the slicer selection, rank them, for the top 4 show in a chart and combine everyone else greater than rank 4 into an others group for the chart.

First I need to rank them, So I created a measure:

RANKX ( ALL(DimTest[ClientName]), SUMX(RELATEDTABLE(FactTest), [LineTtl]) )

 This works fine, when I look at the measure, it displays the correct rank.

So I turn that into an IF() statement as a calculated column, if rank < 4, client name, else other; however it isn't correctly grouping the "Others" or displaying the rank 4 names.

To debug, I used the above measure as a calcualted column to see what it was evaluating, and I found it was somehow doing a LINE COUNT of all the entries,  in the FACT table rather actually SUM and Ranking??

Here is some sample data

SQL code to generate Data

SET NOCOUNT ON; SET DATEFORMAT DMY;
GO

DROP TABLE IF EXISTS dbo.DimTest;
GO
CREATE TABLE dbo.DimTest
	( Id INT NOT NULL
	, ClientName VARCHAR(100) NOT NULL
	, SectionId  INT NOT NULL);
GO
DROP TABLE IF EXISTS dbo.FactTest;
GO
CREATE TABLE dbo.FactTest
	( SectionId INT NOT NULL
	, LineTtl INT NOT NULL)
GO

DECLARE @table TABLE 
		( Id INT NOT NULL
		, ClientName VARCHAR(100) NOT NULL
		, SectionId INT NOT NULL
		, LineTtl INT NOT NULL);

WITH	CTE
		(Id, ClientName, Cnt, Total, x)
AS		(
		SELECT 1, 'Client A', 4, 6000000, 1
			UNION ALL
		SELECT	2, 'Client B', 6, 3000000, 1
			UNION ALL
		SELECT	3, 'Client C', 1, 10000000, 1
			UNION ALL
		SELECT	4, 'Client D', 9, 4000000, 1
		)
,		_re
		(Id, ClientName, Cnt, Total, x, SectionId, lineTtl)
AS		(
		SELECT	Id, ClientName, Cnt, Total, x, LEFT(ABS(CHECKSUM(NEWID())), 5), c.Total / c.Cnt
		FROM	cte AS c
				UNION ALL
		SELECT	Id, ClientName, Cnt, Total, x + 1, LEFT(ABS(CHECKSUM(NEWID())), 5), _re.lineTtl
		FROM	_re
		where	x < cnt
		)

INSERT	@table
		( 
		Id, ClientName, SectionId, LineTtl
		)
SELECT	Id, ClientName, SectionId, lineTtl
FROM	_re;


INSERT	dbo.DimTest (Id, ClientName, SectionId)
SELECT	Id, ClientName, SectionId FROM @table;

INSERT	dbo.FactTest (SectionId, LineTtl)
SELECT	SectionId, lineTtl FROM @table


SELECT * FROM dbo.DimTest;
SELECT * FROM dbo.FactTest