The comparative problem with the AI in Sins is that it doesn't handle resources or objectively analyze power differences between ships in a method acceptable for large variation in mechanics.
Vanilla is balanced in such a fashion that you rarely see it. Casualties are quickly replaced because ships are very inexpensive aside from capital ships. Casualties among those expensive, hard to replace ships are rare by comparison.
With SOA2, the difference between the frigates and capitals is less. Casualties among those significantly less comparably durable capitals are higher, casualties among the frigates are expensive to replace. That it doesn't recognize four Excelsiors as a significant threat to a colony capital ship exacerbates the problem. They also blow up faster in SOA2 than in vanilla, which decreases the survival rate when fleeing, although this is partially mitigated by the lessened chargeup times for jumping.
The more irrelevant or easily prevented casualties are, the better the AI will behave. This works out quite well for games that mirror the Sins design of small frigates and large capitals(SOGE is actually harder than vanilla with the exception of poor defense management), but poorly for more homogenized fleets like the Federation where even the smallest ships are substantial investments.
