You have it completely the wrong way round. Watch the fight again, and pause exactly at 0:48. Quite clearly we see Windu moving in-front of Sidious and Fisto moving behind him. In the next couple of seconds Sidious turns around (because he can manipulate the flow of the battle as he pleases) and takes out Fisto before whipping back around to deflect Windu's incoming attack. Windu is powerless to stop him. One could argue that if Fisto had been attacking from the sides he would have had a better chance, but against such a skilled opponent you don't have a choice in what direction you attack from, you move with the flow of the battle.
No, Windu tried to move behind Sidious to attack him from different angles, which let Fisto need to face Sidious head on.
Team work could help a lot, like Anakin+Obi Wan VS Dooku in EP III, and a better example, Maul brothers VS Sidious, they did hold much longer than the other 3 when Sidious was dual wielding, is Savage and Maul much stronger than Tiin, Kolar and Fisto? Not likely.
Force Speed is not Sith only, especially he had to change direction and kill Kolar. Sidious' speed didn't even own Maul brothers that badly, when the space was much bigger.
And he was in combat, he could keep stick with Sidious, keep face him and take his attack, which would work greatly, Vaapad power up with the Dark Side power it faced.
He simply wasn't well prepared, and didn't form a good team.
The question is simply. Is Savage and Maul much stronger than Tiin, Kolar and Fisto? No, and none of them are as powerful as Windu. So it means the four Jedi didn't form a good team.
The Anakin and Kenobi example is not a good one, because alone Anakin was superior to Dooku and Kenobi a match for him. This scenario is different, Windu and Sidious are equals and the rest are simply eclipsed. As such teamwork will only get you so far, because if your opponent focuses on you even for a second - you are dead.
Now concerning Force speed, its pretty simple. Without Vaapad Windu just isn't as fast as Sidious, so there is no chance that he could have intercepted those attacks which in itself is a difficult task to perform. Sidious caught them of guard, and capitalised on that weakness through superior speed. This had nothing to do with tactics, but simply superior abilities, no matter what there tactics were, unless they were expecting such an attack, their is nothing that could be done. But again are you implying Windu is some kind of old, slow fool? Who just watched?
Concerning Maul and Savage. I'd just point out that at least in my opinion, Maul is a better duelist than Fisto, Tinn and Kolar, and Savage is a more powerful Force user. Which places them in much better stead for taking him on. Savage wiped the floor with all Jedi he faced, including Jedi Council Member Adi Gallia, and Maul was skilled enough to compete with the likes of Vader and Dooku if given a chance. So yes, combined they are considerably stronger. The duel itself is clear evidence of this. Tactics alone won't help you against such a powerful opponent.
Regardless their are several differences and considerations that should be taken into account here:
1. Maul and Savage were ready, they were not caught off guard like the Jedi Strike Team, and therefore more able of withstanding Sidious' initial assault.
2. Maul and Savage have a great deal of experience fighting with each other and the former trained thelatter, much like Anakin and Kenobi. And like that pair capitalized on that strength with considerable effect against opponents such as Dooku, as Maul and Savage did against Sidious. Windu, Kolar, Tinn and Fisto have worked together in the past, but not against challenging opponents, and they don't share the master-apprentice bond.
3. Sidious was toying with them. The determination and anger we see in Sidious' face when fighting the Jedi is not present when he fights Maul and Savage, instead he cackles and seems much more relaxed. He certainly starts fighting harder as the battle progresses, but every tiny advantage allows Maul and Savage to survive a little longer.
4. I feel the need to say this again, but don't underestimate Maul. He could likely take on two of the Jedi in said strike team and win, like he did against Kenobi and Jinn with ease. He took on Sidious one on one and put him on the backfoot, he even managed to score a hit. He is an exceptional, exceptional lightsaber duelist.
Windu could certainly have picked a more skilled team of duelists i.e. Kenobi, Yoda etc. but if he had chosen duelists of the same caliber, but simply different skill sets - the outcome would have been very much the same.