For Tashigi and Gina, in fact, Oda has given us a clear answer on many details. They are two different people. There may be another reason why they are so similar.
When Guina died, Sauron clearly saw Guina's body, although his face was covered. But Guina was the only girl in the Dojo at that time. Guina's hairstyle and figure were different from others, so she couldn't find body double in a short time.
Sauron took Guina's knife when he left? One word "what way"? This sword is the sword that Guina has been carrying around since she was a child, which is of great significance to Guina.
Sabre is the most important thing for a swordsman, not to mention a sharp knife like "harmony". If Guina plays dead and leaves, she will definitely leave with the word "He Dao" and will not let go of this knife. Tashigi was a girl who liked all kinds of precious knives when she was a child. What's the name of the book she read? Tatsu Yamashiro? It means knife.
In addition, Tashigi has a bamboo knife for training, and she wears Taoist training clothes. But judging from the mark on the chest, it's a? Cross? Mark, it's completely different from Sauron's Dojo Mark.
I believe many sea fans think that guina actually went to sea first, which is totally untrue.
Because swords and knives are so important to a swordsman, how can you leave without them? Does this mean giving up your position? Especially in Japan, not to mention the swordsman's knife, but even the carpenter's shuttle is regarded as life. How can it be separated for no reason? Such a sacrifice is a bit big.
This alone reduces the possibility that Tashigi is Gina to a very low level.