Setting that value to 250 resolved just about all my concerns related to the delay selecting troops, much appreciated for the advice. I ran across a few more questions/concerns while playing most of yesterday though:
1) Migrants. Maybe I took too long to expand, but I've got 4 Migrants I can't do anything with. Every single city I have or I conquer is already filled to max.
2) Sea combat. I I'm stuck unable to get ahead against the Athenians because of their enormous numbers and a lack of understanding on how sea battles play out. As far as I can tell ships engage one on one, even if I have more than they do, and somewhere around 1/2 of the time my ships win. The problem with this system comes out that I reached a point where they've consolidated enough that one on front I've got at least 7 ships in the cities adjacent to me, and in another I've got at least 12. I've stripped down my forces to try and deal with the sea threat and at most I've managed to scrounge up the resources for 11 total and I can't make any headway. I can't even concentrate my entire fleet and stop Athenian raids with how the combat system works, let alone actually fight back at this point. Is my only recourse to just keep advancing on the ground and go back to keeping large garrisons ready to respond to coastal raids?
3) So far I've got the Western Frontier to the edge Amphripolis in the East, and Stropsko to just outside Thermopylae and I'm almost at the point where I'm forcing myself to continue. I get attacked via six different vectors (not counting sea raids, which adds at least two if I respond by sea, and at least four if I let them land, which they usually do regardless of what my fleet does) and so far three of those I have to constantly watch/manage or they'll overrun me (or destroy my food supplies to those front, causing roughly the same effect). In addition to that, I get raided often enough that I haven't had a moment of rest to relax and focus on forward planning in over an hour of game time, there is always a fight going on somewhere. I can still push forward even despite the constant fighting, but that just feels like a chore. I think my major problem here goes back to Peltasts and Javelin troops. If I'm paying attention then engaging them isn't challenging or particular difficult, just extremely frustrating because the difference between them being wiped off he face of the earth and my troops being routed is whether I'm there to tell them what to do. I suspect if I could use cavalry to deal with them, it wouldn't be so bad, but all my frontier cities are at choke points, and Cavalry units are too wide to maneuver, they end up getting caught by the troops my infantry are fighting when trying to maneuver around to hit the ranged units.
I probably need to hold off playing for a bit, because just starting up the game and THINKING about what I've got ahead of me this morning causes me heartburn. Yet on the other hand, I've loved the game up until now, can imagine having even more fun, and want to play more. Its just when I go from "want to play" to "here's what I'm going to do", it all falls apart.
4) City connections. I've long since given up connecting everything to my cities, which I suspect is a design decision, but its still proving to be more problematic than seems right. My current focus is to have all my farms and cities linked up, and any extra room goes to mines. I've still got a few Villa's connected, but I'm slowly getting rid of those as they just aren't worth it now that I've got mines sitting unused. However any of my forward cities where I have to station troops never get enough food supplies to last them through winter because my directly connected cities can't pump enough food forward to keep them supplied and build up a reserve for winter. I could used sheep, I know, but while working with sheep is at least interesting when managing offensive operations, it is just plain tedious keeping track of all my current cities and seeing if they need a sheep or not, running out to capture a new one and planning well enough in advance to ensure they get there in time.
As I was writing this up, something occurred to me that I could probably test in game but... (see item #3) If I connect a forward city to a city far away, does that affect the total amount of supplies per week that can travel along the path?