Could it be possible....?

[Seventh Sama]

OP: to answer your question and confusion. Of course Juubi back then as Complete made of nine tailed beasts would be as powerfull as Current one Juubi made of Nine tailed beasts... and that is fact.

Child forms of tailed beasts are not affecting decrease in power of Juubi who fought against Hagoromo and that is right for sure.
However Child forms may be either result of Bad/weak state of Hagoromo when he tried to create them using Creation of all things but remember that Hagoromo divided COMPLETE JUUBI's chakra into nine parts so even these children form of tailed beasts should be as powerfull as current ones as chakra should be as potent as now.... unless Hagoromo used Juubi's chakra to create Moon or something which caused Juubi to decrease in power for some time being and in result child forms of tailed beasts were created instead of adults. In other words Tailed beasts were not as powerfull as current ones... but their chakra would regenerate and when reached full then it would on the same level as current beasts.

I hope it clear your doubts, OP

exactly... if you need any more info. read up waltz post in that link T Bogard provided. He explains everything nicely.

 

[SageOfTheTenPaths]

Nice post, but nah, Rikudou sennin had creation of all things, until Madara gets that he is not close to Rikudou sennin,
Creation of al things = Game over

 

[Namikun]

Not at all....