As you mentioned 2 different IP networks here 1st 192.168.15.1 and 172.16.1.1 . But in above configuration none of the router interface is configured with 192.168.15.0 network. You had only created physical connections . As per my understanding route...
No distribution layer required, Just core and access switch. Core switch with same config running HSRP between them. Access switch connected to both core switch.You have to check your server support NC teaming or not if yes you can configure one sing...
