tactical or positional players

Doesn't good position lead to good tactics? In that case, can a player ever truly be said to be either a tactical or positional player? The only other way I can see to get tactics is via a blunder, and in that case, what constitutes a blunder? And if a tactic isn't instantly playable, isn't positional maneuvering necessary?

You are right that both are interconnected. "Positional" means skilled at evaluating a position. "Tactical" means skilled at evaluating a tactic. Tactics are transitions between positions and positions are starting and ending points of tactics.

I'd only add that tactics needn't make use of blunders from the opponent or a better position. They require neither gaining advantage nor responding to opponent's mistakes. Those would be exploitations, not tactics. It's a matter of phrazing but it's worth differentiating those anyway.

A blunder would be: a move which leads to either (if one sports himself a tactician) a favorable combination for the opponent, or (if one sports himself a positional player) a favorable position for the opponent. Favorable meaning perceptibly better than the one (combination / position) resulting from the best for the opponent of the rest of his possible moves.

TL;DR: one can sport himself as whichever of those qualifications he'd feel like or consider more meritable.

We use positional play to set up a strong position and tactics arise from that strength. But we can also play strictly tactically by opening up the position, by trading pawns for example or possibly even sacrificing pieces, and then using our pieces to exploit those openings. Examples of good tactical players are Morphy and Tal, you can find their games in the databases and by replaying them you will see brilliant tactics. If you want to see examples of a player getting good positions and taking advantage of the accumalted strengths you can check out the games of Steinitz. Fischer is an example of a player who studied the openings and when a player made even the slightest error in the opening, he was able to chop him up tactically. Playing positionally is basically setting up a good static pawn position and then pushing up one of the pawns to force an opening that can then be taken advantage of tactically. Playing dynamically is concentrating on piece position, putting Knights in holes, opening files and placing Rooks on them, opening diagonals for Bishops and so forth. Dynamic play is tactical play. A good player does all of the above, he plays positionally to get a good position, opens up the position, puts his pieces in good places and launches a vicious tactical attack!