We have different types of tables and currently all of them are in one tablespace(user).
Broadly the tables can be catogarized in following catagories:

avg_row_len*num_rows*1.2(from dba_tables)
1.high insert and high updates 7mb
2.high inserts and deletes/moderate updates 2mb
3.high inserts/low updates or look up tables 64k

So should I create these three catogores of tables with different inital extents ?

Do I need to have these three catogories in separate tablespaces to avoid any fragmentation?
or I can have them in one tablespace and just create the tables with diff initial extents?