I think I understand what you are asking about here. If I am wrong, please let me know, and I'll try to repost as needed.
The Constant-Current Regulating Supply mentioned, sounds quite similar to the method of powering the older Series Street Lighting Systems
, found in Residential Tracts back in the late 50's thru early 70's (the ones in my area were upgraded in 1976 to normal parallel circuit Lighting, using Mercury Vapor HID lamps in Cobra Heads, then these were upgraded to HPS Lamps in 1980).
These were Incandescent Lamps, connected in a Series String.
Load Amperes on the Series String was 6.6 Amps. Unsure of the Voltage rating per individual Lamps, but judging from their brightness at stable operation, must have been around 50VAC - as they appeared similar to some 300 Watt large sized "A" type Incandescent Lamps in output Light.
On these, if one Lamp failed, a "Blow Out" link would automatically fall in place across the Lamp's Terminals, effectively reclosing the Circuit and regaining Continuity.
When this occured, the Regulating Transformer would adjust output Voltage, by means of a movable core (I think - need to verify and reply later).
The way this Transformer "Found" out there was a change in the load Circuit was due to an increased load current - or a change in the Reflected Impedance
of the Secondary Circuit.
Since there was a lower total connected Impedance from losing one fixed Resistance in the Series String (the Lamp which failed and was bypassed), the current drawn by the circuit increased while at the same Voltage.
This resulted in an imbalance within the Reg. Transformer, so it "Fixed" this problem by adjusting its self, until the output Voltage matched what was required to push 6.6 Amperes through the connected load.
OK, so much for that!
Basically, a higher Reactance is like a higher Resistance - higher value will result in lower current flow at a fixed Voltage.
That's one of the things related to a given Reactance (X is the symbol for a Reactance).
One of the most useful results on an AC is how a Reactance effects the Frequency.
Lower Hz pass easier through an Inductive Reactance (XL), whereas higher Hz pass easier through a Capacitive Reactance (XC).BTW; having XL + XC, or one or both Reactances with a pure Resistance "R" in a given circuit is where the term Impedance "Z" comes into play for AC.
As explained in your example with the series connections of Isolated Transformers (10 Transformers connected to the Regulating Transformer), if the load on the Secondary side is high, the XL on the Primary side will also be low. It will reflect the Impedance of the Secondary side's load.
If there's no load on the Secondary side, the Primary side will reflect a large Impedance - and result in a high XL on the Primary winding.
Lowering the Voltage to the Primary will reduce the XL on that Primary winding, resulting in a higher current flowing within the Series circuit - yet it would be difficult to push the needed 6.6 Amps through this Primary winding, as it would act like a Linear Reactor or "Choke" coil, plus result in a very high Secondary Voltage with an open Secondary circuit.
But if the Secondary of that Transformer was closed (like what was done in the Series Street Lighting example above), then the Primary winding would reflect a very low Impedance to the source -resulting in a very low XL on the Primary winding - which would allow the required 6.6 Amps to flow through it with little opposition.
The Regulating Transformer would adjust the output Voltage to suit, and the results would be an apparent power - in Volt-Amps, as was drawn previously (and is required by the connected loads).
It's getting late, so let me quit here and wait for your reply.
Let me know if I covered the areas enough or at all, or if you have further questions.