So your theory is that in PoS currencies like NXT, whales use a special client to coordinate their choices when the chain forks, and impose these to smaller nodes? Well, NXT's Economic Clustering, as far as I know, is indeed doing something similar ("it shows you where the whales are"), but it doesn't force other nodes to follow their chain. So I interpret it to be different than centralized coordination. For whales (and other nodes, too), however, it may be rational to follow other whales because they're those who most lose in a chain split event.

There’s no mathematical nor algorithmic way to decide amongst all the potential forks that can be forged within any interval, which is the legitimate one. In PoS unlike in PoW, due to the nothing-at-stake problem because the interval is relative to the autonomous choice of timestamp and nothing is burned, then forgers (i.e. stake-based miners) have the incentive to build their forged blocks on top of every forged block. The choice of of which forged blocks to mine upon is either based on enforcement power (e.g. the grouping of stake with the most stake) else PoS devolves as stated. Even if the stake grouping with the most stake is not a majority of the stake, it must necessarily be coordinated (not randomly autonomous) in order to maintain the longest chain—thus fulfills the definition of an oligarchy in control. Algorithmic changes that attempt to penalize those who forge on more than chain are necessarily always going to be flawed and not resolve the issue, because there is nothing-at-stake. Transactions as Proof-of-Stake (TaPoS) isn’t a solution to this near-term forking divergence issue. Andrew Poelstra failed to note that penalizing for signing multiple histories doesn’t resolve the power vacuum that no unique near-term history is distinguished from all the others in the absence of coordination and thus definitionally an oligarchy:


I explained in more detail along with explanatory condemnation of NEM, Nxt, and IOTA. The leadership election process for PoS is ambiguous. Even if the potential stakers are ranked such that the one with the highest ranking forges the next block, and forgers are penalized for forging on more than one chain, this is a security hole because the highest ranked staker can pretend to be offline and so the next ranked must forge the next block. Then after honest stakers have done so, the higher ranked staker forges a block orphaning those, which creates an ambiguity over who is cheating. Propagation is not objective in an asynchronous network. The Ouroboros^† “provably secure” PoS alternative may solve this coordination issue by creating objective entropy via secure multiparty computation presuming a majority of the stake is honest, but requires a majority of the stake to remain online and the network to remain bounded synchronous for said majority.

I'm speculating that you will say that Litecoin is not really "innovative" necessarily because the devs are mostly working on tech that was theorized & proposed for Bitcoin proper, but I'm curious to hear your thoughts.