You need to apply tactics in SPQR to survive.
Basically Premarius shouldnt engage Germans, in reality Rome never fought with the Germans until Later in the Empire, if they did they probably would have been butchered. lol
Premarius is good to hold off the gauls maybe take a province or 2 but really you should go after Carthage just as Rome did.
But since your campaign was rushed and you are now facing germans try this tactic for ALL barbarians when fighting them. Place you Hastatii in a Shield wall 2 rank thick formation all 5 units.
Then have your 2-4 Velites/archer/slingers behind the Shield wall.
Next place your Principes all 5 of them in block formation behind the velites.
Make sure all units have Fire at will engaged.
Ok after that Triarii all 3 units for backup and finishing up to the enemy.
On the wings 1 unit of cavalry each. This is a standard Roman formation and works well in SPQR for Barbarians.
Look in the SPQR_Readme folder in your RTW folder, in there you will find extra goodies on formations and the README which is also in this forum posted.
Play the game slow, build and apply realistic strategies, read the forum for advice, there are alot of old thread that have answers. The mod was made to play in a realistic manner with logistics being an important part and tactics on the battlefield. No other Mod allows the Battle Time SPQR does, which allows for realistic gameplay and a realistic FEEL to the battles.
SPQR battles or ferious and massive, speed but mroe important Timing and tactics will when the day. In RTW speed was everything, battles over in 5 minutes, in SPQR battles can be as long as 1.5 hours! most are 30 minutes to an hour. Sieges are Massive in SPQR especially with the script activated, you will need to have more than 1 legion and for sure Backup units to soften the city before the Final Assault!
What I do is attack with the auxilia units tagging along behind the legions, then in battle when I am done using them, archer etc I send them retreating and this then allows the Legion without a general so it waits on the sidelines to come in and assault the town. Soudns realistic doesnt it? Thats what SPQR is ALL about.
Lt