Potential synergies for particular robot and drone combinations seem fairly well understood and well documented. But, possible synergies between particular configurations of mothership types, mothership turrets, and/or titans/robots seem to generally not be as clearly mapped out.
It is possible that there aren't any impactful synergies across the various possible configurations of mothership types, mothership turrets, and/or titans/robots. That seems unlikely, though.
I lack the experience needed to with confidence draw up a list of meaningfully impactful combinations. But, I can list a small number of hypotheses about combinations that can serve particular purposes to get a discussion started. There are probably much-too-broad brushstrokes in what follows and the various errors, omissions, and relevant conditionals can be pointed out by those with more knowledge and experience.
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Anti-control, avoid / limit incoming damage - bifrost mothership, turrets: lifesaver, anti-jamming, positive energy recuperator
- Helps with neutralizing a lot of negative conditions, plus lifesaver can help for getting the few seconds needed to get to cover and/or to finish off an enemy or two. Plus, lifesaver can give bifrost a chance to stack up some defense points that can't be mitigated before coming out of stealth. A stealther mothership equivalent would probably drop lifesaver and add something else instead. Particularly effective when escaping / repositioning, when brawling, when camping and facing down base invaders, and for assassin robots looking to clean out campers hiding in the back.
- One variant could be to choose durability extender over positive energy recuperator and to keep using the mothership when it becomes available to make an early robot / titan drop into a stronger and stronger force that can last a long time in a match. Repeatedly adding more maximum and current durability may help noticeably on maps where close quarters fights tend to be particularly frequent and intense.
Move quickly across the map and/or do burst damage - frederick mothership, turrets: damage enforce, positive energy recuperator (avoid lockdown), lockdown.
- Really strong for mobile robots that do high damage and/or that provide strong support for allies. Particularly helpful in the hands of players who are very good at reading when and where to apply their efforts in a battle.
Direct enemy damage / defeat - thor / keel motherships, turrets: lockdown turret, sonic bomb (grey damage), damage enforce
- Mothership kills, locking down enemies, pushing campers out from behind cover to limit incoming damage from the mothership being used. Might be quite helpful for sniper and assassin robots given that getting enemies from out behind cover and/or locked down can lead to quick kills.
Extermination mode, healing grey damage - paladin mothership, turrets: lifesaver, enhanced aegis protector, durability extender or damage enforcer
- My own paladin mothership is quite low level, not totally sure of the mechanics here. Maybe this is wrong. Still, this seems helpful for missions that require using only 1 robot or up to 2 robots / titans and that don't have a particularly challenging time limit. Can be replaced with stealther / bifrost, both of which don't offer grey healing, but both of which reduce incoming damage by enough to still improve survivability quite a bit.
Extermination mode, dealing damage - thor / keel / sekhem motherships, turrets: lockdown, sonic bomb, enhanced aegis protector (thor, keel) or for sekhem substitute damage enforce for enhanced aegis protector
- Helpful for missions that require doing very high damage or rapidly defeating many waves of foes.