Well, as an Estonian who loves Darkest Hour, I guess I have no other choice than to agree and help you
To be honest, I have always hoped that someone would modify the Baltic states as at the moment I have no interest to play with them (not because they have 0,01% chance of surviving the WWII, but more cause the lack of both historical and ahistoric events).
For example, Estonia has no fleet ... That's historically inaccurate. For example, in 1934 Estonia ordered 2 submarines from United Kingdom (Most of the money came from the national fundraising (locals were giving money) project to buy the ships). Both Kalev and Lembit were finished in 1936 and reached Estonia in 1937. They were rather similar to British submarines, but due to some differences (as they were individual projects), they were caled Kalev Class.
About the Finnish, Estonian, Latvian, Lithuanian and Polish alliance, it was considered by Estonian Goverment. Especially Estonian, Latvian, Lithuanian alliance. Now being realistic, an alliance of Estonia, Latvia, Lithuani, Poland and Finland would actually be able to wield quite a big army in terms of numbers and both Germany and USSR would have to consider their actions a bit more.
In reality, many Estonians fought in the Winter War, supporting the Finnish. They returned to Estonia after Finnish victory and most of them became rebels (forest brothers).