Hex tiles vs. a full Board?

Yes, it is a limited space. Do you want a big game or a small game? Both have their own potential players.

I don't think you know what you want.

The art style says "light and casual" to me, so I'd expect it to be a small game, like an hour play time.

This confuses me. You want the game to be faster, and making a bigger board would achieve that? I'd think a smaller board would better achieve what you wanted. Maybe you should revisit how movement occurs in your game. Movement mechanics strictly exist to restrict what a player is allowed to do and always slow games down. If you want a faster game, maybe you could abstract a board. Maybe the board is five (randomly chosen number) rows and any number of characters can occupy a row. This has the potential to make movement simpler (only up and down) and faster (fewer choices).

I have a hard time imagining that a board with randomized hexes would make the game faster. Setup alone is slower.

Hope this helps!

If you want it to be more streamlined and faster, hexes seem to be in direct conflict with that idea. Hexes with unique terrain properties would add even more complexity and, subsequently, would tack on even more play time. A standardized board would make for a more streamlined, faster game in every circumstance I can currently think of.

And, to be clear, I personally prefer hexes simply for the variety and added level of interesting decisions that could arise (depending on the game's rules and mechanics).

However, there is much to be said for simple, streamlined, short games. If a game is fun and has good replay value while having a minimal amount of complexity, and doesn't require players to invest their entire night in playing it, it is more likely to be a popular game (and probably much harder to design). It will be more accessible, easier to teach, and therefore perfect for introducing games to new players. Also, simple games can still be deep in their own ways.

Ultimately, what is your goal? Decide on what type of game you WANT to make. Then, apply the appropriate requirements in all aspects of the design (including the board).

Good luck!

I've taken the opposite route with my game. It started as a modular map consisting of 12 different tiles that were aligned to create a modular board. This is where I started because I like the variability of modular game boards. In order to make the game more streamlined I removed lots of things that weren't necessary and I found that the modular tiles was one of these things. I think the reason my game plays just as well on a predefined game board is that it didn't make enough use of the modular setup and that variability was enough with the predefined board.

I think that in order to make use of the variability in modular boards you need different terrain that affects movement. The best uses of modular boards I've seen are the ones that have roads on the edges and where you can only travel along these roads. This means the setup isn't completely random but you must make sure the roads align when building the board. My point is that if creating a modular game board ends up with a set of terrain tiles that are just organized in different patterns you are probably not making enough use of the modularity and could as well use a predefined map. But if there are rules when building the game board that create maps with widely different game experiences then you're using it the right way.

It may seem like an obvious point but modular game boards do not by default mean good variation. It must be designed the right way. It took me a number of redesigns to realize this.

Since it is a wargame and you would like to have a modular board.

Here is how I handle it:
My wargame has different races/units and they are depending on terrain design.
I use the rule, that each player may add each their own modular boardparts. That will be their homeground. So, imbalances in the game are strategically reduced, by players choices. If an enemy invades their home, they have an home advantage.
Either by their strategy choice, or race/units, or both.

This even works well if you have symetrical armies.

The worst combination is of course symetrical boards with different races.

Symetrical armies on a symetrical board is an utopia game.

Is MODULAR "mats" that have hex squares on them. But you can orient each mat in four (4) different positions. I believe that if you have four (4) mats that's 16 different combinations.

It's in-between the concept of TILES and BOARD. It is also probably the cheapest options out of all three.

It's more flexible than a static board but less flexible that tiles. But it could be the option you are looking for - if it's something do-able and not too expensive...