F5 SNAT an option?

I am working a new install of ECS.  The network guys are pushing back on my putting the customer data interfaces (network segmentation setup) "behind" the F5, i.e. the F5 is the default gateway on the "backside" of the F5.  they want the F5 to sit wherever and the ECS to sit wherever and them use SNAT to make sure routing happens properly.  This should avoid packets going back to the server directly from ECS because ECS will always see the F5 as the source.  Is this supportable or does the ECS have to be behind a F5?

Chad...