combat experience doesn't really mean anything in the NV when we have base naruto tricking people like Kakuzu. Minato's use of FTG is also superior to Tobirama's where the later has only shown the ability to use a single marking at a time while minato can spam them.
That is due to Naruto's unpredictability. Battle experience certainly does play a huge role in this fight as superior battle experience means Tobirama has a better application of FTG in comparison to Minato even if Minato has added a little extra to it. Even then, we have Madara praising Onoki's battle experience as the main reason why Onoki performed at such a higher level compared to the other Kage.
True, Minato does use more markings, but that doesn't necessarily mean Tobirama's inferior. We've seen how well Tobirama applied Hiraishin with a single marking against both Juubito and Madara with Tobirama displaying Hiraishin against the latter to enhance his own performance in a straight up battle in Taijutsu.
And aside from that, having multiple markings wasn't shown to be effective against much stronger opponents as it did absolutely nothing against Juubito. The most important aspect was reaction speed which Tobirama was more effective in. Why does Tobirama have superior reaction speed?
1. Tobirama flickered to KCM Minato's position and grabbed the TSB that tagged KCM Minato before KCM Minato could grab it himself and KCM Minato was caught in the action of grabbing it himself prior to Tobirama flickering to his location and that was done with merely a clone who was stated to be less reactive than the original.
2. Tobirama managed to tag Juubito from 5-10m with precise timing the moment before Juubito could slice him in half. KCM Minato then comments about Juubito's speed after his Shunshin rather than during it meaning that
he didn't see a thing despite having an outside perspective of things.
3. Juubito didn't notice that Tobirama had tagged him, neither did KCM Minato and KCM Naruto as Tobirama had to explain to them how his clone warped to Juubito and warped him away. Juubito didn't notice Tobirama tagging him as he was shocked when Tobirama warped to him and his attention was directed towards Minato meaning that he did witness Tobirama grabbing the TSB.
4. Tobirama placed multiple tags on Juubito w/o KCM Minato even perceiving it. This is exemplified when Tobirama demanded Minato to "warp" and his eyes dilated as he was shocked by Tobirama's command until the next panel reveals that he placed multiple tags on Juubito.
Tobirama's reaction speed is significantly higher than KCM Minato's, so Tobirama wins this overall.