Why are some city names, when named after people, given -sk suffix, but others aren't?

Question

Two examples:

1. Yekaterinburg was renamed to Sverdlovsk in 1924, after the man Yakov Sverdlov. Notice the -sk prefix.

2. Orenburg was renamed to Chkalov in 1938, after the man Valery Chkalov. Notice this name doesn't have the -sk suffix.

I am wondering why. Both names end in a v, but one is given an -sk suffix, and the other isn't. Is there some rule about this? Does the -sk suffix mean anything?

Note: I have a similar question. That one is more about general city names, but this one is more of a specific case because Chkalov has no suffix, prefix, or any modifications to the name whatsoever. I'm wondering why. "Chkalovsk" sounds better to me, like Sverdlovsk.

Answer 1

There's no grammatical rule in Russian that specifies city name generation based on person names. It's rather random or based on historical context.

For example, in early soviet times Stalingrad (now Volgograd), Stalino (now Donetsk) and Stalinsk (now Novokuznetsk) existed simultaneously.

Answer 2

It seems like in modern Russian language there is a "hierarchy" of city name's forms, according to a degree of importance and respectability. If we name a city after a person, for example "Иванов", then the hierarchy will look like this:

Ивановград > Иванов > Ивановск > Иваново, Ивановский > Ивановка

This hierarchy appear to be settled about 1930s. According to the unwritten rules, if a prominent person (Иванов) dies, and we name a sizeable city after him, it's preferable to name it "Ивановград" or "Иванов", but not "Ивановск". Свердловск was renamed in 1924, and Киров in 1934, and since that time it looks like the tradition of "-ск" is getting deprecated in favor of just [Family Name]. But for small towns it is still Ok to get the "-ск" suffix.

Suffix "-град", while being the most prominent, also sounds pompous and is not widely used.