Hi ravitejagundu,
It all depends on your contract.
There should ideally be a single control instance and you can have multiple execution instances.
How many you can setup is in your hands if the servers are hosted with you on-prem.
If the execution instances are with Adobe, provisioning will happen based on your contract and hardware sizing. Please check with support how many execution instances you have.
Connecting multiple execution to a single control is fairly easy and you can do so by following the documentation you shared https://docs.campaign.adobe.com/doc/AC/en/MCE_Instance_configuration_Creating_a_shared_connection.html
If it is on-prem support cannot assist with the infrastructure setup as it is outside their remit. you will probably need to work with Adobe consulting or an implementation partner.
Regards,
Vipul