(D1-1) is not the same. (D1-1) says only that there is a largest referent of what is {me ko'a}.
It is a tautology, and says nothing particular. The difference from {ro'oi da su'o pa mei} is that the speaker fixes {ko'a} to be {su'o pa mei}: once {ko'a} is fixed, the other thing that is {me ko'a} is not called {su'o pa mei}. (D1-1) says nothing, but a kind of dummy to make (D1) (D2) (D3) be meaningful also to non-individual.
When another condition {ije da me de} is added to (D1-1), (D1-1) is not a tautology, and {ko'a} is an individual (not only {ko'a su'o pa mei} but also {ko'a pa mei}, though): then the conditions are equivalent to {ro'oi da su'o pa mei}, which makes {ko'a su'o pa mei} always true.
As long as talking about among theory, (D1-1)+{ije da me de} is not a logical axiom or equivalent, though it is necessary for comforming to mereology with atoms.
(D1-1) ko'a su'o pa mei := su'oi da poi me ko'a ku'o ro'oi de poi me ko'a zo'u de me da
(D1) ko'a su'o N mei := su'oi da poi me ko'a ku'o su'oi de poi me ko'a zo'u ge da su'o N-1 mei gi de na me da(D2) ko'a N mei := ko'a su'o N mei gi'e nai su'o N+1 mei(D3) lo PA broda := zo'e noi ke'a PA mei gi'e brodaYes, and please note that (D1-1) is not equivatent to {ro'oi da su'o pa mei}.
Do you agree that with just those definitions:ko'a pa mei= ko'a su'o pa mei gi'e nai su'o re mei= na ku ko'a su'o re mei= na ku su'oi da poi me ko'a su'oi de poi me ko'a zo'u ge da su'o pa mei gi de na me da= ro'oi da poi me ko'a ro'oi de poi me ko'a na ku zo'u na ku de me da= ro'oi da poi me ko'a ro'oi de poi me ko'a zo'u de me daThe result requires {ro'oi da su'o pa mei}.
As I discussed above, (D1-1) is a kind of dummy to say {ko'a su'o pa mei} for a particular ko'a. With (D1-1), once ko'a is said to be {su'o pa mei}, {ro'oi da su'o pa mei} is not true, and we don't get the same result.
With a dummy defintion (D1-1), "PA mei" is not meaningless even for non-individual.Set {B su'o pa mei} according to (D1-1). Suppose {C na me B}. From a property of {jo'u}, {B me B jo'u C} and {C me B jo'u C}. Then {B jo'u C su'o re mei} according to (D1).
A non-atomist speaker must fix a referent of sumti to be {su'o pa mei}. For enjoying atomicity, just add a condition {ije da me de} to (D1-1), then it becomes clear that {ko'a} is an individual.
Starting with {ro'oi da su'o pa mei} is useful, but excludes non-individual from expressions {lo PA broda}. (D1-1) makes (D1) (D2) (D3) available also to non-individual.