spoilers

this is the total number of war assets from the salarians if u kill wrex and destroy maelons cure 125+35+25+150+8=343 125 from saving the salarian concilor in me1 35 for letting kirahee die and talking to lt tolen at stg base in me3 25 from mordin if u persuade him that curing the genophage is a bad idea with wreav in charge and eve dead 150 from sabotaging the cure and 8 from a salarian side mission and also get the krogan too with this 25+25+50+50+305+40+300=795 25 from wreav 25 from grunt if he survived me2 and his loyalty mission was completed 50 from arlak company 50 from n7 cerberus attack 345 from krogan clans and also speaking with diana allers and also the 40 from krogan side mission 300 clan urdnot so add them together and u get a total war asset amount of 1138 instead of curing the genophage and loosing the extra salarian support 875+169 which equals to 1044 so kill wrex destroy maelons data all it will do is change dialogue nothing bad

spoilers

this is the total number of war assets from the Salarians:

125 from saving the Salarian councilor in me1 
35  for letting Kirahee die and talking to Lt. Tolen at the STG base in me3 
25  from Mordin if you persuade him that curing the genophage is a bad 
      idea with Wreav in charge and Eve dead 
150 from sabotaging the cure and 
8   from a Salarian side mission
= 343

You also get the Krogan too with this

25  from Wreav 
25  from Grunt if he survived me2 and his loyalty mission was completed 
50  from Arlak company 
50  from n7 Cerberus attack 
345 from Krogan clans and also speaking with Diana Allers 
40  from Krogan side mission 
300 Clan Urdnot 
=795

Add them together and you get a total war asset amount of 1138.

When you cure the genophage and lose the extra Salarian support, you get 875+169 which equals to 1044.

So kill Wrex and destroy Maelon's data. All it will do is change dialog, nothing bad.