This ain't cool at all. The railway authorities are the ones making us think this way. Splitting by states is just not gonna work for Indian Railways, but nowadays trains are being given out due to political pressure. Politicians support only those trains that will get them votes, ignoring the fact that some regions at the boundary suffer. People like CIC/Singrauli are hit the hardest.
It's true not every state can have its own zone, it's just not gonna work economically. From the list given, KR is not needed as Goa falls under SWR. Other zones in the list will cover areas under the respective zonal headquarters' jurisdictions.
KRCL could take up the responsibility of building new lines in challenging areas like J&K, North East, Leh, Himachal, etc. It's not feasible to operate train services in one small state separately, it's just not economical.

Mujhe ye chahiye nahi. Lekin rail administration hi public ko aisa sochne ke liye dabba rahi hai. State wise divisions IR ke liye practically possible nahi hai, lekin aajkal trains sirf political pressure ke bina nahi milti. Netas sirf un trains ka support karte hain jo unke vote bank ko serve karte hain, zonal boundary regions ke liye unhe koi farak nahi padta. Sabse bada nuksan uthane wala CIC/Singrauli hai. Sab states apna alag zone nahi rakh sakti. Yeh economic taur par feasible nahi hai. Di gayi list mein, KR ki zarurat nahi hai, Goa SWR ke andar aayega. Baaki list zonal Hq state jurisdiction se judi areas ko serve karegi. KRCL ko geographically difficult areas mein naye lines chalane ka kaam mil sakta hai; J&K, North East, Leh, Himachal aadi. Ek chhote state ke liye alag se train chalana uski arthvyavastha ke liye thik nahi hoga.

When they're expanding infra, adding new lines, and planning to hit places like Gangtok and Imphal, setting up new divisions and zones ain't impossible. Even NR is thinking about laying down tracks in Leh Ladakh. Shit is crucial to reorganize and set up bomb division and zone setup for proper handling. Can't rely on just a few switches in the HQ to run the show. South is also getting more train tracks, so ain't gonna cut it with just 1 or 2 zones. Loads of new tracks pending, like Madurai to Thoothukudi via Aruppukkottai, East coast lines like Karaikal to Peralam, and Mayilduthurai to Tharangambadi to Thirunallar. Arcot lines such as Tindivanam to Nagari, Kallakurichi to Ulundurpettai, and Kongu region waiting on Dharmapuri to Morappur, Tirupathur to Krishnagiri to Hosur. Kerala's in on it with Guruvayur to Thirunnavaya to skip SRR, and a Sabari line from Kottayam to Sabarimala. Karnataka and AP need their own separate discussion to dig into. Gotta seriously plan and shuffle things around based on future needs and ops.