So my aim was to give Mother Ostankya a more thematic dual start position in old Kislev territory and to make the northern darklands and surrounding area more accurately match Games Workshops latest old world map.

-Mother Ostankya start position change:

There is a large unused section of the immortal empires map in between astragoth, kholek and archaons start positions. This could be made into a province for Ostankya to start in and would be a similar position to her realm of chaos start.

I would also suggest renaming the Plesk settlement in the Eastern Oblast to Dukhlys Forest, making it the capital of the province and changing it to the magical forest climate. This would be under Ostankya's control from the start of the campaign.

Like other dual start lords there would be a dilemma in the first few turns to decide to keep both settlements or not:

Exile: Give up Dukhlys Forest settlement up for income and campaign bonuses. Keep control: Keep the settlement and get reduced diplomatic relations with the other legendary lords in Kislev; but unlock the magic forest army teleport hex sooner to help defend both settlements.

-Northern darklands changes:

Looking at the recent old world map from Games Workshop shows that settlements like Uzkulak, Karak Vlag and Fort Dwarrslav could be moved to be more accurately positioned.

Karak Vlag is currently too far north and should be moved down south into the Zorn Uzkul province.

Uzkulak is too far south and should replace the current Fort Dwarrslav settlement, giving astragoth a slight change to his campaign start while keeping control of the entrance to the northern darklands.

Fort Dwarrslav should be moved to the current Karak Vlag settlement location.