I am running two SQL Servers 2012 (for Always On) under the same domain account and would like to know what are the downsides in doing so. Few articles that I have read prior setting up the servers suggest different domain account for each sql server and services it will be running. The downside to that method is each sql server must be also setup to have access to another sql server through that account. However, with single domain account all the sql servers already have the access since they are running under same account. Of-course, the biggest pitfall the articles pointed out is lower security, well, due to all sql servers sharing the account.
How critical is this, single domain account for all sql servers, in small environments and what are the other pitfalls?