I have no problem with a diversity of monsters - but the targets of the TI should be, by a good margin, the most common monsters there. Set the map to have a good density of TI monsters, then add in some monsters chosen to be annoying to deal with at the same time as the TI monsters. If the density of the TI monsters is good, you can afford to be a little evil with the other monsters - The TI monsters are earth? Well, how bout some fire monsters so they'll need an extra killer (or a non-elemental killer). TI monsters are lots of different elements (ex, dimiks)? They'll be using neutral against it, so throw in some ghosts. Slow TI monsters? Add some fast nuisince monsters so they'll need a class with endure to mob 'em (in moderation, that could actually kill it). And there's no wrong time for annoying debuffs (AoE bleeding, dispel, traps) or painful attacks of opposite element of the ones the TI monsters use. I think this would make things more interesting and challenging.
Ex: Ice dungeon? Wind Ghosts (SP trap) and Beholders!
Thors? How about a fire-and-ice theme by adding some of those water monsters from ygg tree, the ones with the nasty waterball...
And so on. Necromancers are really annoying (can't kill them with physical damage in a reasonable length of time - would people bother killing them? Or just ignore them, and let them nip at the party's heels until they die from the attacks directed at the TI monsters. That;s the natural answer, but their crit wounds would make that harder to get away with)
But you first need to have a sufficient density of the TI monster. TI monster should always greatly outnumber the junk/nuisance monsters. IMO, a good rule of thumb would be that a really competent party should be able to (just barely) complete a TI in half an hour if they hurry, and a lousy party should still be able to pull it off in an hour or less,assuming reasonable effort. That's what people have the attention span for. I think avg of 3-4 monsters per screen probably isn't enough to make this happen - but it might be if the map encourages people not to wander over eachother's paths. Keep in mind that the chance to engage in heavy mobbing is fun, much more fun than sparse, wimpy "mobs"
Edited by DrAzzy, 08 May 2012 - 06:23 PM.