You don't need a seriously leveled sov to take down Ophidians, I do it often with some magic and some spearmen backing up my sov. But sounds like you just got dealt a bad hand by the RMG

I am not sure what type of Sov.  the OP has. As mentioned even a caster/warlock type can get by with some spearmen type early units.  Just heal or enchant up if you are not a melee type.  I said before the random number generator is a merciless god.  Sometimes it can be good to you and other times it can deal you crap repeatedly. 

I have played a few games with the new world generation at startup.  Balanced world with moderate settings.  Sometimes you can get stuck between another empire/kingdom and a wildland, or you can endup in a fertile spot, settle and see another fertile place just 8 or 9 tiles in a cardinal direction away from your first spot.  It's all random. If it says 4 or 6 on medium.  I play 4 if I want time to build/ settle. I play 6 if I don't. 

Also, to say that the RNG is merciless is a cop out.  This isn't a roguelike.  It's a TBS.  People expect some level of fair play, and have since Civ I.  If you make a game that it takes you an hour or two to figure out that you were guaranteed to lose from the beginning...  Well, that's a pretty badly designed game.  You can make the monsters that guard lairs of secondary expansions weaker.  They just haven't done that.  Probably because it's more complicated that just scattering random monsters everywhere.

Map generation is important.  You want to know what sort of reviews FE is going to get?  Watch what happens when your reviewer, who's got other stuff to do gets dealt a totally crap game.  And how often does that happen?  Because I must have seen it in like 60% of my playthroughs.  Deadly monsters guarding secondaries.  Almost peninsula capitals with *nowhere* to go.  Stuck between two empires.   

I'm not fiddling with options.  I'm default everything.

Strange they aren't immune to attack magic, wonder if it's a bug

No creature is "Immune to Magic" they just have +100 spell resistance so usually just take half damage from magical damage spells, also you can at some late-point, with a super levelled hero, brute force your way through immune to magic with enough spell mastery.

Sincerely
~ Kongdej

I agree, I want a 2nd place for a city too, I usually quit when I can't get it cause I know I will be spanked... Unless I focus on an all out mage hero... or is playing a kingdom faction...

UMBER must be EMPIRE! (its more like a warcry )

Sincerely
~ Kongdej

Agreed Ophids are tough.

And I also prefer to take them on only midgame, as early game requires a serious change in research (spears and not civ like mining) as well as production priority.

I must admit that I generally go the 'suicide' route, of racing a pioneer to spot and found the city. Most of the time the Ophids will simply wander out of your territory without attacking ur city. And yes thats without masterscout option. Its borked, but the way it is atm. I really do hope it will be changed. Best way to change it would be an area around lair, where no outpost/city could be settled imo.

Last game I planted two outposts next to 2 strong ogre troll lairs. Both simply wandered off and left my hero with the loot, I really hope this will be changed into ogres making a try on the outpost before returning to lair at least.....will update once i have found the screenshot

 edit: inserted screenshot

Do monsters even attack outposts? I've never seen it

If your 4X game doesn't allow you to expand half the time, then yes, your 4X game is broken.  It's the first X.  This shouldn't be such a controversial line of thought.  

You want to stick Strong/Deadly monsters on secondaries on High difficulties?  Go for it.  On default settings?  Why would you do that?  It kills player progress, which is key to any game design.  Here's the worst idea for a game ever.  It's called: "You Sometimes Can't Reach Level 2."  (By the way, the same argument applies to the way the food mechanic works in this game... max food winds up killing your sense of city progress way too early.)

I also wasn't under the impression that FE was going to be the Dark Souls of TBSes.  I like FE because I liked Master of Magic.  Not because it's stupidly difficult at easy difficulties.  I know it's awesome to Ironman everything, but some people don't ascribe to that method of playing.  There's a line between randomness being an enjoyable aspect of a game and randomness being a useless waste of everyone's time.

I dunno, my sovereign usually have whacked all the monsters for me to notice anything.

Sincerely
~ Kongdej