I have played fighters across editions, and I am not a big fan of a complex fighters for several reasons that I think are worth considering.
1) Maneuvers like Disarm, Bull Rushing and Trip often don't apply. Disarming a dragon poses obvious difficulties. Bull Rushing a Great Wyrm or Tripping a Purple Worm is also tricky, especially for a human sized character. In 3e, these tactics were effectively impossible. 4e solved that problem by saying "ignore the fluff, apply the mechanic"..... but that causes suspension of disbelief problems and, from what I've seen of 5e, doesn't seem to fit its philosophy.
2) Maneuvers like Disarm, Bull Rushing and Trip kind of suck. By and large, they are a 1 round-control effect. With 5e's easier movement, these maneuvers are even weaker than in previous editions. Having one party member spend his action for a chance at countering 1 foe's action only works if there is a particular, high priority foe. Such foes are likely to be highly resistant to the tactics (see note 1).
3) Swords shouldn't be stat-sticks. A fighter who holds a sword in one hand while spending his time Bull Rushing enemies like bowling-pins is just a jumped up monk. This can be dealt with by making the maneuvers free-action riders on a main attack, but that still leaves the problem of the general suckitude of most fighter-type maneuvers.
4) Improvisation is hard. It is easy and seductive to come up with scenarios where improvisation is awesome. It is hard to come with improvisation for a random scenario, especially round after round. This is a very important fact. Also,
to quote GURPS, "If sand in the face worked every time, barbarian warriors would leave their swords at home and carry bags of sand instead!"
Focussing the fighter on improvisation poses a very real risk of becoming a running gag.
There is room for a slighly-more-complex fighter, but it isn't an easy bit of design space to do well, or at all. A better strategy is to polish the simple fighter, and allow for a few modest bits of complex fighter for free. They generally won't be worth using so they need to be free to avoid being a trap build. On the other hand, they will be rare, so the times they do come up will be that much more rewarding.
1) Maneuvers like Disarm, Bull Rushing and Trip often don't apply. Disarming a dragon poses obvious difficulties. Bull Rushing a Great Wyrm or Tripping a Purple Worm is also tricky, especially for a human sized character. In 3e, these tactics were effectively impossible. 4e solved that problem by saying "ignore the fluff, apply the mechanic"..... but that causes suspension of disbelief problems and, from what I've seen of 5e, doesn't seem to fit its philosophy.
2) Maneuvers like Disarm, Bull Rushing and Trip kind of suck. By and large, they are a 1 round-control effect. With 5e's easier movement, these maneuvers are even weaker than in previous editions. Having one party member spend his action for a chance at countering 1 foe's action only works if there is a particular, high priority foe. Such foes are likely to be highly resistant to the tactics (see note 1).
3) Swords shouldn't be stat-sticks. A fighter who holds a sword in one hand while spending his time Bull Rushing enemies like bowling-pins is just a jumped up monk. This can be dealt with by making the maneuvers free-action riders on a main attack, but that still leaves the problem of the general suckitude of most fighter-type maneuvers.
4) Improvisation is hard. It is easy and seductive to come up with scenarios where improvisation is awesome. It is hard to come with improvisation for a random scenario, especially round after round. This is a very important fact. Also,
to quote GURPS, "If sand in the face worked every time, barbarian warriors would leave their swords at home and carry bags of sand instead!"
Focussing the fighter on improvisation poses a very real risk of becoming a running gag.
There is room for a slighly-more-complex fighter, but it isn't an easy bit of design space to do well, or at all. A better strategy is to polish the simple fighter, and allow for a few modest bits of complex fighter for free. They generally won't be worth using so they need to be free to avoid being a trap build. On the other hand, they will be rare, so the times they do come up will be that much more rewarding.