I'm doing something similar right now in my script. I have (from previous processing) three lists that include coordinates that I am creating three point FC, and getting coordinates in XY-projection, and Geographic coord in DD, DDM and DMS.....(using Project, addxy, and Convert Coordinate Notation—Help | ArcGIS for Desktop) then merging the three files with JoinField. really messy if I let ArcGIS autoname the fields, since they are the same in each. So I'm going to alter the field names to include "pt1", "pt2", etc, and change the length of the auto TEXT fields from 255 to 15. As I mentioned, just starting to work on this. But I am also deleting fields.
Some tools that may help you...(Look at the code samples)
ListFields—Help | ArcGIS for Desktop
Fyi..my input starts like
pt1List = [[104, 259572.28396514762, 1569679.2337295527, u'Contour', 2333, 711, 3338], [102, 307382.1354489387, 1540435.947750746, u'Contour', 5738, 1749, 3338], [103, 318046.4257102255, 1572115.318007391, u'Contour', 5646, 1721, 3338]]
pt2List = [[104, 261920.13532314647, 1571191.8980065093], [102, 310325.1529914262, 1538520.823783757], [103, 318832.6403342534, 1572402.314232631]]
pt3List = [[104, 262729.2297764599, 1574104.0470867334], [102, 311161.3833612903, 1542535.1787147326], [103, 320759.5157311091, 1571095.6504666873]]
and my current output is....
>>> outFCdms = 'tmppt1final'
... aaa = arcpy.ListFields(outFCdms)
... for i in aaa:
... print(i.name, i.type, i.length)
(u'OID', u'OID', 4)
(u'Shape', u'Geometry', 0)
(u'PtID', u'SmallInteger', 2)
(u'TransType', u'String', 25)
(u'elev_ft', u'SmallInteger', 2)
(u'elev_m', u'SmallInteger', 2)
(u'xyProjID', u'SmallInteger', 2)
(u'x', u'Double', 8)
(u'y', u'Double', 8)
(u'ddlat', u'Double', 8)
(u'ddlong', u'Double', 8)
(u'POINT_X', u'Double', 8)
(u'POINT_Y', u'Double', 8)
(u'DDLat_1', u'Double', 8)
(u'DDLon', u'Double', 8)
(u'DDMLat', u'String', 255)
(u'DDMLon', u'String', 255)
(u'DMSLat', u'String', 255)
(u'DMSLon', u'String', 255)
(u'ddlat_12', u'Double', 8) # etc.
And this is something that will be run numerous times....so I will need to script it too....but for me, I'll do it at the FC before my jooining the 3 tables. This is probably not exactly what you are doing, but probably similar. If you give an example of where you are starting and what you would like in the end, it would be easier for others to help. I can share what I come up with too.