|Why do you need 3 routers?|
Unless you have a specific need for more than one router (ie: multiple separate subnets) then you should be using a single router and a single switch. Or, multiple switches if necessary (ie: physically extend network beyond the limits of a single network cables maximum segment length).
The preferred method would be one router combined with one switch that has enough ports to support all present clients and a few extra's for future growth.
As to congestion and crashing. they shouldn't if they're configured and interconnected properly.
Before going any further, you should tell me what you're doing and why you think you need more than one router and I can help you better.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.