>>5914437On top of what this anon said
>>5914446 the earlier you start, the more time you'll have to get promoted up to commanding more survivable ships before things get bad.
The earlier dates give you more outer-colony battles to distinguish yourself in, such as New Constantinople and the glassing of Kholo. With outer colony battles generally being smaller engagements due to the lack of defensive infrastructure around those colonies. Once you start reaching the inner colonies and prepared defenses, the covenant are gonna start bringing out larger fleets, and your ability to swing things on your own merit is gonna start falling off.
On top of that it affects what kind of ships are available. With the fewer and fewer CMA / pre-war vessels being available as time goes on. And that's a big one as the Sins of The Prophets guys made some <span class="mu-i">beautiful</span> CMA and pre-war ships that would just go to waste.