What you've done is by no means wrong, just a personal preference. 
 
If it were me, I would have each flex going into a union, one above the elbow on the right, and one above the branch of the tee. This allows you to completely remove the drain rail for servicing and/or removal the sump. 
 
Like I said, it's a personal preference. 
		
	
		
		
		
		
			
		
		
		
		
	
		
		
	
	
	 |