Hi - as someone who's been playtesting each patch for several months I think I've got a pretty good grasp of early game. Here's my advice:

• First two techs to research are Equipment and Leather armor. This allows you to wield oak spears and gear your sovereign or champions to tank effectively for awhile. A champion duked out in all leather armor with an axe and shield can run with like 15 defense early game. This is more than adequate to fight off monsters and early units from othe factions. The normal units I build are:
• Start - Staff for weapon and no armor - design and build two of those and garrison your capital
• After Equipment - Oak spear and padded cuirass - this allows good defense against spider hordes and awesome attack early game
• After Leather Armor - Oak spear and leather cuirass - same as above but 1 better defense value
• First spell to research is arcane weapon. I can't emphasize enough how important this is. Arcane weapon is a 1 casting cost and 1 maint spell that gives +5 attack. That's a HUGE attack buff early game. For example, staff wielding units have an attack of 5. This buff doubles their attack to 10. Oak spear units have an attack of 9 and the buff increases their attack 50%. HUGE! The other thing - cast it when you need it (i.e. about to attack or be attacked) and then dispel it when not needed. The fact that the casting cost equals the maintenance cost means you should never leave it on idly.
• Make your sovereign or champions the "tank" and supplement offense with cheap garrison units with high attack/low defense - let the tanks absorb the counter attacks in tactical combat and use the cheap units buffed with arcane weapon deal out the damage without suffering counter attack 

It's how I conquer 1-2 factions early on in the ridiculous level game. Please see reply #27 of this thread for my saved games of patch 1.19j: https://forums.elementalgame.com/404664. If you're playing the latest 1.19j patch, feel free to download those saved games and take a peek at my methodology over time. I haven't really been able to play deep into mid or late game lately because of all the new patches but that's ok. I'd really like the OOM and bugs worked out so we can move onto 1.3 content.

Goal should be to take 1-2 factions out early and then you have a solid base (2-3 capital starting locations with all the resources that go with it) to conquer the rest of the map. I also run with a custom sovereign based on bard/charisma. Why? Because it allows me to hire heroes cheaply to do the fighting while the sovereign charisma buffs prestige thus rapidly expands the settlement ZOC's which nullify monster spawns. Anyway hope this is helpful. There are certainly other ways to play the game but it's a style that I've found successful and personally enjoy.

[Edit] Also recommend at least 4 production of materials in your capital. Extremely important early game so you can spam the cheap high attack/low defense garrison units. Later settlements won't need 4 materials in each but early game proper materials production is key.

Thank you both for your replies.

Desraider, I'm playing on novice level because just as I was ready to move up, after playing several games, I ran into the issues I described.

AlLanMandragorn, clearly some of my problems are with how I do my early game research. I've never even considered the methodology you described, but will give them a shot.

Neither of you has quite addressed the question of why the factions I encounter are consistently so much stronger than I am.

I'll be interested to see how things work out with a change in strategy, and also at a higher level.

I would also suggest you pay little heed to the game generated power ratings.  I consistently beat the game on hard and extreme difficulty where my power rating lags behind the computer opponents anywhere from 150-200 points.

You are doing tactical battles, right?  As Allan posted above, your superior play in TC will turn the tide against a much larger foe.  I also recommend a few ice elementals to help freeze more powerful enemies until your archers take them down.  It is more reliable than Grip of Winter and causes some damage to boot. 

Load up a tank hero with healing nectar too, it doesn't seem to cost action points to have them drink potions...

Try Murteas cantrips and magic mods and Kenata's Updated Weapons... both will give you more TC options.

And when you use arcane weapon on a 4 man archer squad it is even more HUGER

Have fun storming the castle!