I assume you are talking about how to train WC fighters within 18 months. After that 18 months, you can teach them all the forms that you want to teach.
I don't believe spartan warriors have solo form training in their program.
I'd be willing to bet they took a given technique and worked the hell out of it...both solo and with partner training and ultimately on the battlfield.
That solo training is form training.
I think that might be where we're having a disconnect.
WC forms are not like other MA forms.
Having had pretty extensive forms training in another CMA pre WC, I know this to be true.
Other systems forms are the encyclopedias for that given system.
WC forms are more akin to a dictionary, or as I like to put it, a list of things to practice.
Running through the Siu Nim Tao for example, is not practicing the form.
It's simply going through the list of what to practice.
To truly practice SNT or any WC form, it's better to take a given movement and practice it solo to work the gross kinks out of it, practice drills with a partner to further refine it, then apply it in sparring.
Then you put that movement back on the shelf and pull out the next one and wash-rinse-repeat.