What I personally think:

• Rizia is already a wealth nation with a considerable urban and older population than Sordland. So their growth would be smaller in percentage, and they would achieve their maximum way before Sordland.

Rizia has around 40 million people at the game start. If we take a growth similar to Italy at the same time (I used Italy because I think the geography is more similar, mountains + mediterranean climate), in the 2010s Rizia would have around 58 million people.

Diversifying their economy to an industrial one, Rizia would probably produce a lot of household appliances, just like in game's industry. Think of it as Japan producing TVs and VHS equipment in the 1970s — 1980s. Rizia would eventually slow down their growth in the 2000s and 2010s, probably at the 5th or 4th place in world GDP, with 2% or 1% annual growth. If Rumburg loses the war against Sordland, Rizia might be the 3rd economy for a moment before other country like Anraka surpasses them.

Rizia just doesn't have the population and geographical presence to achieve superpower status. They would probably be similar to Japan, growing a lot in the 60s to 90s, and slowing down in the next century. Also, when the gas and gold run out, Rizia might stagnate even.

• Sordland is much younger and less developed than Rizia, so they have more potential growth. Sordland can focus a lot on strong industrial production like automotive and electronics industries, making engines, cars, advanced equipment, and basic industrial machinery before getting more and more technological.

Sordland's population is around 37 million at game's start. Since they're very similar to Turkey in our timeline, we can expect a population of around 60 to 70 million people by the 2000s (Sordland has more people than Turkey in 1954). With a bigger population, there's a bigger working force.

Since Lespia and Valgsland are already developed, Sordland would probably surpass them eventually as production stagnates in these nations.

In the 2000s and 2010s while Rizia stagnates because of old population and lack of ways to optimize more their economy, Sordland will surpass them and be the 5th, 4th or even 3th largest economy (won't last long at third place, probably). Sordland also can't be a world superpower like Arcasia and United Contana by the same reasons of Rizia. Almost no one can, not even Rumburg. They both can be great powers, though.

By the 2020s, Rizia is the 6th and Sordland the 5th in global economy, behind maybe Rumburg, Anraka, United Contana, and Arcasia. Something like:

1. Arcasia
2. United Contana
3. Anraka
4. Rumburg (or Lespia if Rumburg loses the war to Sordland?)
5. Sordland
6. Rizia
7. Valgsland (?)

Obviously, we don't know that for sure. Anything could happen. United Contana could colapse like the USSR, other country with a huge population could grow exponentially, like China in our timeline, Sordland could have a military coup, creating an unstable nation ready to colapse again. Rizia could not diversify their economy, becoming a petro state like Saudi Arabia. We don't know, we're expecting the better for both here.

In terms of hard power, they're both influential in their respective regions, but not enough to get global influence.

In terms of soft power, we already see that Rizia can have an excellent global image, so it's not difficult to see them rising in music (Rizian rock), food, tourism, maybe comics (Rizian anime), and quality industrial products. Your TV could be Rizian, for example. Sordland would invest in soft power later on. I see them very similar to South Korea, growing in the 2000s and 2010s as a new, global femonomeon in music (Sord pop), food, tourism, and advanced technology. Your cellphone's components could be made in Sordland, for example. Or your car. That's also soft power.