Can two subwoofers reduce a bass problem?

Yes, but, << whispers>> have you tried bass traps + EQ?  It's like magic.

Yes. Here's why.

The reason we have to move subs around is one sub always causes lumpy bass, some areas way louder than others. So you move the sub trying to find the least lumpy location. Which changes constantly depending on the frequency. This happens no matter how great or powerful or expensive a sub you buy. 

It also happens when you use more subs. However, and this is a big however, having more subs lets you run each one a lot lower volume. So one of the four is too loud and lumpy at one frequency at one location, way too quiet everywhere else. Big deal. No longer matters. Because you have three more. Each of which is at a different location causing different lumps or modes and not nearly loud enough everywhere else. 

But with four all the lumpiness averages out to something quite smooth. Its possible with four to have bass that is both deep and powerful and tight and articulate, as well as smooth. Much more so than you could possibly get with any single sub no matter how good.

Also with just one sub you have just one crossover or EQ. But with four you can adjust each one independently of the others. That's if you run four powered subs. Or if you do like me and some others and run two per amp, or four per amp, whatever. Main thing is any way you do it four beats one even when total cost is held equal.

@OP, 
Yes, using 2 or more subs help with room nodes.
I would PM Duke (audiokinesis), he manufactures the Swarm system.
Though I know you probably don't want to invest in that, I think Duke will be able to steer you in the right direction with regards to sub placement.
Bob

4 is better than 2, and 2 is better than 1, yet in my system one REL S/5 SHO works great...friend with almost identical system sounds best with 2 REL S/3 SHO...so, it depends...

It's interesting that your able to narrow down the problem frequencies.

You should be able to get a decent low frequency presentation at the listening position with one subwoofer by locating your rooms greatest mode using the Crawl method.
https://www.youtube.com/watch?v=AV3oLLMgS-M

During this test you might want to map out all your rooms modes in the event you add multiple subs. 
For reasonably priced long interconnects check out Blue Jeans Cable or Monoprice. Good luck with it.