Pausanias on Achaean armament, ca. 200 BCE

[hoplite14gr]

This is a photo of "Tarentine" horsemen.
There is no evidence that even the horsemen of the Archaic period depicted as mounted hoplites carry shields of the same weight as infantry shields.

The persian spear was shorer than the Greek but there are limits to the spear length that can be balanced in one hand.

"Tou Xerxou grapsantos pempson ta hopla antegrapse molon lave".
Plutarch moralia "Laconian proverbs"
I do not thing that Plutarch means to surrender only the shields.

Plus "epimekestera hopla" in what context?

L. hate de êdê tôn Achaiôn aphorôntôn es auton kai ta panta ekeinon poioumenôn, tois tetagmenois autôn en tôi pezôi metebale tôn hoplôn tên skeuên: phorountas gar mikra doratia kai epimêkestera hopla kata tous Keltikous thureous ê ta gerra ta Persôn, epeise thôrakas te enduesthai kai epitithesthai knêmidas, pros de aspisin Argolikais chrêsthai kai tois dorasi megalois. [2] Machanidou de en Lakedaimoni anaphuntos turannou kai authis polemou tois Achaiois pros Lakedaimonious kai Machanidan sunestêkotos, hêgeito men tou Achaïkou Philopoimên: ginomenês de pros Mantineiai machês Lakedaimoniôn men hoi psiloi tous askeuous tôn Achaiôn nikôsi kai pheugousin autois epekeito ho Machanidas, têi de phalangi ho Philopoimên tôn pezôn trepetai tôn Lakedaimoniôn tous hoplitas kai anachôrounti apo tês diôxeôs Machanidai suntuchôn apoktinnusin auton.

Here he used the term hopla for shields in general.
Archaic Acheans had a hoplite class. Hellenistic Acheans had "regressed" into peltasts.
In the Hellenistic period after viewing Pyrrus and Antiochus pahalnxes ravaging Peloponessos I can reasonably accept rearming into hoplites.
He also new of Heronea and Megaolpolis.

Here he used the term hopla for shields in general.
Archaic Acheans had a hoplite class. Hellenistic Acheans had "regressed" into peltasts.

Plutrarch Phliopoimin 9, 10 also in army reformations

In the Hellenistic period after viewing Pyrrus and Antiochus pahalnxes ravaging Peloponessos I can reasonably accept rearming into hoplites.
He also knew of Heronea and Megaolpolis.

Kind regards