Title is pretty self explanatory but I would love to see the Black Templars added as a customization option for the Adeptus Astartes. I realize that not every chapter can be added because of how many there are, but I feel it is a really missed opportunity to not have a chapter with the largest fleet of the Adeptus Astartes included in a space combat game.
I will edit the exact stats of ships later on when I have time
From my limited experience playing as SM it can be incredibly effective in 2v2 as a more supportive fleet. If the other player on your team is using an offensive fleet you can use the boarding action from cruisers to take key ships out of the fight.
If one of the enemy admirals brings 1 or 2 large ships you can basically wipe out his whole fleet in 1-2 boarding actions.
In a 1v1 it still isn't that bad with the right ship composition but you can still get bad match ups like any other faction.
The SM ships are fairly mobile and have decent armour and weapons however the faction is not built around burst damage or ships that can stay in the fight for an incredibly long time. The ships are designed around boarding actions. When engaging enemy ships they have the speed to close the gap for boarding and decent enough defence to survive heavy damage long enough to get the job done. While in ship to ship combat you can do steady damage to the enemy ships but won't be the best at this role.
Battle Barges: Not good in 2v2 due to such a massive point cost although could work well as a flagship in 1v1. Using this in 2v2 trying to do a boarding heavy build its still ineffective due to only being able to basically only field a fleet of 1-3 ships.
Cruisers: The best ship class for this faction and what makes them great in 2v2. You can bring up to 3 of these for incredibly powerful boarding actions. Using honour the chapter and regular boarding you can turn enemy ships into hulks in seconds. The speed of these ships is decent and I find that using brace for impact these ships have suprisingly good survival even in large fights.
Light Cruisers: These ships are centered around a single build in 2v2 which is stealth and mobility. Due to the light cruisers and cruisers point difference being very low the only reason you would use light cruisers is to do stealth boarding and hit and run attacks. The advantage these ships have compared to cruisers however is the hangar bays these ships. They are fast but do not last nearly as long as cruisers in a fight. In 1v1 you can use these ships to keep stealthed light carriers around to try and counter enemy fighter attacks.
Escorts: Average scouting and stealth ships like most other factions, they get the job done fine.
Space Marines great in 2v2 for boarding. More challenging in 1v1