Random spawn mode is no good, that would totally screw up the mechanics of ltw >.<. You'd be removing all of the skill factor : |.
I'm talking about round robin but circulating every single round. So you send to the person in front of you first round, then 2 in front of you next, then 3, then 4, etc and just circle around =|. And no, I don't mean circulate every send, I mean circulate every time the round changes (whenever income is given for the round). That would be a setup for a rather pro match =P.
Also, you should be able to buy tactics, like things to make the thing circulate +1, reverse, or circulate -1. This could be very helpful to avoid powerful players or to target weak players.
My personal favorite ltw map employed this, but it only did reversals, meaning you were still stuck in between two players. It also had godly 100% sell back rates, meaning that the beginning game could be really hardcore >: D.
Also have you ever considered this for difficulty? What I did with my old wmw map for difficulty was, rather than scaling the hp or speed on the units (messes up the gameplay pretty badly), I scaled the difficulty of races. This doesn't mean I made races op or weak, I just made them more difficult to play. For example, compare a melee race with highly strategic melee towers and mazing towers to a beam race. The melee race requires extreme exposure on its damaging towers, but you don't need to micro them. The beam towers require less effort to exposure and no micro as well, but are weaker with mazing. Due to high hp regen, you don't want a very large maze, but the melee build focuses on bursts of damage and a very large maze, making it extremely optimal (lots of pure damage) whereas the beam race focuses on lots of damage early on but more maze and less damage later on, making it easier to use for beginners, but not necessarily as optimal in the later portion of the game. Well, I guess that makes the melee race better, but only if the player is good enough to use it. Obviously, a beginner on the melee race would lose in a very major way to a beginner of equal skill on the beam race. However, a master on the beam race would lose to a master on the melee race by a slight amount due to the loss of efficiency in the later portion of the game. The proficiency of the race is traded for ease of use. The easier the race, the less potential it has ^)^. That was my philosophy anyways. The admin would unlock a specific difficulty for the map, be it beginner, intermediate, professional, or hell. Hell mode races were ridiculously hard to use, but had masses of potential. As I mentioned before, only 3 players out of many, many, many players were able to play the hell mode race I made without hours upon hours upon hours of special training. In a match, the 2 masters of around the same skill each played the same hell mode race and tied. Two masters then played against each other, one on beam (beginner) and one on the hell mode race and the one on the hell mode race won. Two beginners, one on the hell mode race and one on the beginner race, then played each other. The beginner on the hell mode race lost after 2 sends (about 45 seconds total, third send was already going in). I think that this is the best way to make a great tower wars map that is friendly to all players of all skill levels : ).
And to give you an idea of the hell mode race.. it had mazing towers for 1 gold each and its first damage tower was 35 gold. However, building this damage tower in a naive way isn't enough to counteract even the weakest monster, so you have to build it for absolute maximal exposure. To mob levels 2 and 3, you had to also finish your hook. This means by the second send, your hook already had to be up (old wmw maps could hook, no bolt or anything). All of the towers sold back for 100%, so you could do quick temp mazes. I was thinking of making hell mode races the only races to be able to sell back for 100% due to the necessity of making temporary mazes on them (damage towers that are only there for 1 round etc). They required an extreme level of skill to use >.<.
So anyways, I'm just wondering if you ever plan to do something like that for this map : ), cuz that would be really awesome ;o. And as I mentioned, upping the hp, speed, or regen or w/e just messes up the game. It doesn't up the difficulty, it just makes it so you have to build more. If anything, it lowers the difficulty of the game as beginners already overbuild in mass. Upping hp in so called "pro" games just lowers the gap between actual pros and actual beginners. If you look at an intermediate player, their biggest issue is underbuilding because they are still trying to find that thin line between overbuilding and underbuilding where they can maximize their income ^)^. I was an intermediate player for like 1 year ;o. Just about every player is beginner. Every once and awhile I'll see an intermediate, but haven't seen a single pro in a long long long long time. If you do proper scaling of difficulty with races or w/e, you could encourage more pros to come about as they try to master hell mode races ; D. It's either that or everyone will play on beginner mode because nobody will be good enough to even handle intermediate, lolz ; P.
I think you need to study tower wars more so that you have a better understanding of the game ^)^.