dual electric fan mounting question ?

I do agree with Krazy, to optimize airflow angular would be best. But for your application as long as it's sealed well and fans can pull a good vacuum and decent cfms I think you will be ok. Most of those expensive polished aftermarket shrouds are same shape you made. Some guys get away with attaching fans to rad with no extra shrouding, I wouldn't hesitate to try as is with rubber seals. Cheers.