What I did is just rush the missile mods.
You’re stock and going to be facing fox3s, but I’d still recommend bringing some chaff so get R-73 then chaff
Can’t remember how many mods each tier is but what I think I did is
R-73
Flares/Chaff
G suit
New Boosters
R-27R
Wings Repair
Cover
R-27ET
R-27ER
Then work through the rest of the performance mods. (I’d recommend compressor or engine first)
Anyway in an uptier I can’t recommend playing for altitude early game, especially with the weak RWR the Su-27 has.
I dont have the Su-27, but this is just my usual pattern for all aircraft where possible
My default is usually chaff, so I can defend myself against SARH/ARH threats if applicable
then grab some form of bomb, so that I can always grind at least something via A2G (especially if I decide to take it into ASB, this is how I grinded most of the Typhoon, FA2, etc)
Then Id grab missiles and any critical A2A mods, like boosters and G-suit.
Unfortunately, you’ll only have a chance at fighting them after unlocking R27s. I think you’d face the enemy before reaching bases to bomb so I don’t recommend bombing personally.
I think the post above covered the right priorities. R73 for self-defence. Chaff and flares obviously. You need G-suit and Boosters to dogfight after the merge.
Unfortunately you’d have to play like a pussy running away and notching every FOX-3. Occasionally you’d join a furball and help your teammates by shooting R73s at the distracted enemy. At this stage you can’t really compete yet, especially against 13.7-14.0
I just finish stock grinding the Su-27 as a new top tier player… 1. R-73 2. R-27T 3. New Booster 4. G-suit 5. Airframe 6. R-27R 7.Cover 8. Wings repair. 9. R-27ET and R-27ER very very powerful then Chaff and flares if you don’t know how to notch for radar missle.