So often we judge the contents of an old Ryuha based on the kata - this may not be without due cause as I would suggest in some Ryuha this is what is practiced (at least nowadays).
We must however consider other training methods may have been just as important, if not more important than kata themselves.
Taking the spear as an easily understandable example, the kata - especially those being against another spear - are often complex what ifs. There is little ‘basic training’ contained therein, little simple target practice.
Does this mean that spearmen practiced no basics? I would suggest not.
The basics were probably practiced ad-nauseam but no kata was required to enshrine simple information, or indeed it is coded into the attack side (first learn to thrust, then you can practice dealing with the thrust).
I would suggest that Kusarigama is similar.
We can, of course, pull out a raft of recurring themes when handling the chain in kata - however, I would put it to you that rather these being the mainstay they are how to handle what will go wrong. The mainstay of the weight and chain should be to cast and strike the opponent, the mainstay of the flail should be to strike and lash the opponent.
This can be practiced simply (and safely) by actually casting/flailing against a target.
Typically the kata contain misses, entanglements, and transitions to grapples - this does not necessarily mean the tactics of the Kusarigama are to miss, entangle or grapple - indeed these may be the worst case scenarios.
I liken this to some BJJ players. The Gracie’s themselves looked at a bottom guard as starting off in one of the worst possible positions but rather than giving up, learning to survive that position. Once people become comfortable in that position they begin seeking it out - somehow the worst case scenario has become a tactic, which is probably not helped by sportification.
This may be true in Kusarigama - the mental picture of entangling the weapon may be appealing to those with visions of fishing the sword out of someone's hands - once you really push this you find the sword takes over control of the chain - it is a problem for the Kusarigama in the most part, not the sword.
You therefore may not want to seek out the positions the kata deal with, they may simply be the positions you will encounter when things invariably go wrong - the original idea may be to simply spear, flail or lash them with the weight again and again.
There are some positions you want to get to and there are some positions you find yourself in - it is problematic to mistake them.
When we consider two-person kata typically there is a winner and a loser, and often the loser is the one who initiates an attack. As I described above there is a danger in taking a Kata as being entirely literal. The more advanced practitioner (in the case of say Isshin Ryu Kusarigamajutsu, the sword) can view the Kata as an instruction on how to attack, typical responses to the attack and how your opponent may try and defeat you.
It would be terribly inefficient to have only one side learning something whilst the other plays the dummy.
It may also be true that in a warrior tradition it is inadvisable to teach something early that you can't defeat. This may sound a little strange but an example I like to use is hand grips in Jujutsu. Disengaging a grip is a useful thing, and easy enough to teach. Although often looked down on by people who train mostly empty-handed, it is also a critical skill when weapons are introduced.
As skills improve, I may initiate a grip, say grabbing the knife hand, with every expectation of the opponent trying to defend the grab - with the full intention of using whatever the opponent does to defend the grip as an entry into an appropriate technique.
In this way Kata are a bit like historical fiction - the information contained within the story in terms of places, events, clothing, and habits may be entirely factual and useful. The story may be entirely fictitious. I can tell the difference between a Spitfire and an ME109, an Enfiled MKIV and an M1A1 from reading Commando comics as a child, the actual stories I don't remember (except that Germans yell 'Got in Himmel' when surprised).
So, a Kata should not always be taken literally, it is not a story to try and reenact in reality, and you shouldn't be disappointed when it doesn't make complete sense - you have to drill down to the marrow to get the most out of it.