hmmm..good question there. Conkleduur and Throh are very similar in stat distribution and can play similar roles.
However, let us take a good look at their base stats first :)
As you can see, very similar indeed, however there are some stat differences that are quite notable. To start with, Throh has a better HP and better bulk overall and will most likely be surviving longerr then Conkledurr
However, Conkledurr is certainly not frail as it has relative bulk, however it's SpDef is quite disappointing but due to Psyshock appearing more often the Psychic nowadays it might be able to survive a neutral one. What makes them both excellent is their bulk and offensive presence, however Conkledurr will be hitting MUCH harder then Throh as a base 140 Attack stat is nothing to joke about as it is almost equal to Zekrom's attack stat
Despite Throh and Conkledurr being quite equal, there is a reason why they are in different tiers.
- Conkledurr is a prefered offensive presence and can deal with many OU threats
- Throh's defensive abilities are certainly not bad, but this become useless in the tier where Conledurr resides
- Conkledurr has a better movepool then Throh
- Despite it's bulk, Throh's weaknesses are very common and it will most likely not stay around that long
- Conkledurr performs better in double battles (utility)
*As you can see Conkledurr has many thinks going for it. However Throh is noted to be the bulkiest fighting type in the whole game barring Arceus-Fighting
You will most likely be finding yourself using Conkledurr over Throh due to it's versality. It is almost as bulky as Throh and it can hit harder then it
However you must take note that they both reside in different tiers, Conkledurr being in the OU tier and Throh in the NU so they are hard to compare as they both do their jobs well in their respective tiers. Despite them being capable of performing the same role, Throh will often serve as a Tank, whiles Conkledurr will often serve as a Trick Room sweeper
However should it ever be so that you were to build a mono-fighting team, I would say that Conkledurr will be proven superior over Throh in that aspect :)