Proxmox cluster multicast with crossover connection over second NIC?

Hi, I´d like to create a proxmox cluster in the data center of my server provider. They said that multicast isn´t possible, but they suggested to connect the two servers I´d like to build the cluster of with a crossover cable at a second network interface card. They say, that I can use multicast on that direct connection then.

Will this setup work? Will it be more difficult to install for me?

Thanks
tabbi