I'm guessing a "hoplite" is spear+shield and pikemen is a guy with a pike.
I don't think spear+shield should be a very effective build, at least in the absence of teamwork. Using a spear with one hand and a shield in the other would be difficult and require a lot of arm strength/stamina. The shorter the spear, the more effective the build should be. Even 1Hing awlpikes is pretty ridiculous. Ideally, spear+shield builds are good in close groups against 2H, against ranged, and non-spear/lance cavalry. Pikemen will suffer against ranged, can outrange lance cav, and are better 1v1 (more attack directions).
Hoplite:Sword + Shield + Spear (other polearms for variety, spear is bread and butter- preferably Red Tassel Spear, the fastest).
Pro: Amazing support. Can defend like a
beast. Cav coming? Turn around and show him your spear and watch how quickly he leaves your archer buddies alone. Other archers an issue? Pull up your Steel shield, Huscarls, or Round shield (depending on preference) and you are an instant source of cover. Teammates fighting an enemy? "LOL I DOWNBLOCK YOU!" That's great until your buddy to your left starts swinging side to side while you constantly thrust. With a high enough speed and a partner, no one should be able to drop their shield, and 2hers should go down pretty quickly between getting poke stunned and missing blocks.
Always stay near your team. If you're interested in some solowork however, drop down to Khergit, or Saranid Leather Armor and grab a buckler. You'll have to semi-manually block arrows and incoming slices, but you will also move like the wind. Use hills and terrain as cover, give enemy ranged a suprise party they will never forget.
Cons: Polearms take a penalty to speed/damage with the shield. Steel shields are
heavy and decrease your mobility. Switching from a polearm to your sidearm when you've been rushed by a 2her is an exercise in fancy footwork, one has to step through (past) the opponent, turn fast enough to block the swing coming, and step back (and have enough ath) to backpedal, switch out, and have the shield up for the next strike. "Lol, downblock forever." You will not be optimal 1v1 and unless you're better at aiming than me you'll be getting assists instead of kills. Assists are fine when that x5 multiplier keeping you company, however.
Dedicated Pikeman100% Polearms. I haven't tried this build yet, but not splitting points between wpf makes your polearms unspeakably swift. With the proper aim one can keep a group of enemy far at bay with a good pike and some timing. I'll flesh this out more after i've actually tried the class, i will say i know there's at least 1 guy who can use the full long pike better in close quarters than i can use a red tassel spear. The number of kills he gets is disgusting and awe inspiring.
For this build you are essentially a 2her with all the problems that entails, but one major benefit: Polearm stun.