If you are thinking that the gun position is at the tip which might create a heavy pivot to the centre of gravity ... then we should look at the old design and compare ... now old design had the same location for the gunning position .
As far as i am informed . A129 used a 3 barrel 20 mm Gatling gun with 500 rounds.
It also used 2 Rolls Royce 2-1004D engines
T129 also uses a 3 barrel Gatling platform with 500 rounds capacity .
It uses LHTEC CTS800-4A Engines which are more powerful than old Rolls Royce engine's
how could this helicopter not be able to handle 20 mm Gatling almost similar to its old version apart from Bullet feeding system sticking out ...
Which is another questionable argument...
Now there are several forms of drag that may cause unstable flight for an aircraft ... there is the parasite drag and induced drag . Bullets sticking out would create problem at a parasite drag stance ...however parasite drag takes effect at high speeds and only create problem then ...which a helicopter isnt even designed to travel at .
Truly i do not see any problem at this time ... if there is stability issues then this would come out at firing range tests ...and there are ways to counter such issues .
On the other hand AH-1W Super Cobra has a stronger General Electric T700-401 engines which is also used at AH-64 Apache and UH-60 Blackhawks ... now this added with the relatively different placement of the gunning position (which is slightly behind the nose ) creates a better stability during gunning .
Although stronger engines means better performance and heavier payload ...it also means expensive operation costs ... The engine T129 uses delivers a good combination of performance to cost ratio with a steady payload . I believe this is a good deal for Turkiye's first attack helicopter project ...and i also believe this will be a stepping stone for greater projects in vehicle weapons system (which would be used in several UAV's ) future helicopter projects and even for jets (avionics wise)