Wet, you need to erase the phrase "p2w" from your mind, it's stopping you from learning to get better at the game because that's all you focus on.

As Luka said Row/column doesn't really matter.

All that matters is action priority. 1, 2, 3, 4.

If I move Mabui up one spot, she'll still be 1st, if I move her foward 1 spot, she'll still be first. If I have more initiative on all 4 team members than my enemy, then my team will only go before the characters in an equal priority slot or lower, Tenten with HIGHER initiative will go before the enemy 2nd, 3rd and 4th team members, not the 1st, no matter how high her initiative. The exception to this is non prompt mysteries which instead take the place of a standard attack, which means since Tenten is a Prompt she will go first before non prompt mysteries.

When it comes to Prompt VS Prompt, you can't go first before a character that is in a higher priority slot, which technically does work based on columns and rows, the only way Tenten in this picture can become Priority 1 is by moving her above Mabui on the same column or forward in front of Mabui. There's a rare situation where if you kill someone and erase them from the fight entirely (Such as by killing them with Beheading Kakashi or Mabui's mystery) then the rest of the team will move up in priority, if my Mabui gets erased, Tenten becomes Priority 1 Mid fight and can start going first with my MC and Mei also moving up a priority slot.

I hope this helps clears things up, Ninja Stars and Initiative do matter in Arena.